Additive manufacturing systems and methods of generating CAD models for additively printing on workpieces

ABSTRACT

An additive manufacturing system may include a controller operably coupled to a vision system and an additive manufacturing machine. The controller may be configured to determine in a library-CAD model, a nominal model-interface traversing a nominal model corresponding to a workpiece, to compare the nominal model-interface of the library-CAD model to a digital representation of a workpiece-interface of the workpiece, where the digital representation has been obtained using the vision system, and to generate a model of an extension segment based at least in part on the nominal model-interface, with the model of the extension segment being configured to be additively printed on the workpiece-interface of the workpiece.

FIELD

The present disclosure generally pertains to additive manufacturingsystems and methods of additively printing on workpieces, and moreparticularly to systems and methods that include a vision systemconfigured to locate workpieces and an additive manufacturing machineconfigured to print on the workpieces.

BACKGROUND

An additive manufacturing machine or system may be utilized to producecomponents according to a three-dimensional computer model. A model ofthe component may be constructed using a computer aided design (CAD)program, and an additive manufacturing machine or system may additivelyprint the component according to the model. With previous additivemanufacturing machines or systems, typically, components are additivelyprinted on a build plate and/or within a build chamber. After theadditive printing process is completed, the components are removed fromthe build plate and/or the build chamber for further processing. Thebuild plate and/or the build chamber are not part of the component beingadditively printed, but rather, the build plate and the build chamberrespectively provide a surface and/or a medium to support componentsduring the additive printing process. As a result, the specific locationof the final additively printed components on the build plate and/orwithin the build chamber may not be of particular importance providedthat the components are successfully printed as intended by the CADmodel.

However, according to the present disclosure, it would be desirable toutilize an additive manufacturing machine or system to additively printonto pre-exiting workpieces, including additively printing onto aplurality of pre-existing workpieces as part of a single build. Whenadditively printing onto such workpieces, it would be desirable foradditive manufacturing machines, systems, and methods to additivelyprint onto pre-existing workpieces with sufficient precision andaccuracy so as to provide near net shape components. Accordingly, thereexists a need for improved additive manufacturing machines and systems,and methods of additively printing on workpieces.

The workpieces contemplated by the present disclosure include originallyfabricated workpieces, as well as workpieces intended to be repaired,rebuilt, upgraded, and so forth, such as machine or device componentsthat may experience damage, wear, and/or degradation throughout theirservice life. It would be desirable to additively print on workpiecessuch as machine or device components so as to repair, rebuild, orupgrade such components. It would also be desirable to additively printon workpieces so as to produce new components such as components thatmay exhibit an enhanced performance or service life.

One example of a machine or device component includes an air foil, suchas a compressor blade or a turbine blade used in a turbomachine. Theseair foils frequently experience damage, wear, and/or degradationthroughout their service life. For example, serviced air foils, such ascompressor blades of a gas turbine engine show erosion, defects, and/orcracks after long term use. Specifically, for example, such blades aresubject to significant high stresses and temperatures which inevitablycause blades to wear over time, particularly near the tip of the blade.For example, blade tips are susceptible to wear or damage from frictionor rubbing between the blade tips and turbomachine shrouds, fromchemical degradation or oxidation from hot gasses, from fatigue causedby cyclic loading and unloading, from diffusion creep of crystallinelattices, and so forth.

Notably, worn or damaged blades may result in machine failure orperformance degradation if not corrected. Specifically, such blades maycause a turbomachine to exhibit reduced operating efficiency as gapsbetween blade tips and turbomachine shrouds may allow gasses to leakthrough the turbomachine stages without being converted to mechanicalenergy. When efficiency drops below specified levels, the turbomachineis typically removed from service for overhaul and repair. Moreover,weakened blades may result in complete fractures and catastrophicfailure of the engine.

As a result, compressor blades for a turbomachine are typically thetarget of frequent inspections, repairs, or replacements. It istypically expensive to replace such blades altogether, however, some canbe repaired for extended lifetime at relatively low cost (as compared toreplacement with entirely new blades). Nevertheless, traditional repairprocesses tend to be labor intensive and time consuming.

For example, a traditional repair process uses a welding/claddingtechnique whereby repair material may be supplied to a repair surface ineither powder or wire form, and the repair material may be melted andbonded to the repair surface using a focused power source such as alaser, e-beam, plasma arc, or the like. However, blades repaired withsuch a welding/cladding technique also undergo tedious post-processingto achieve the target geometry and surface finish. Specifically, due tothe bulky feature size of the welding/cladding repair material bonded tothe repair surface, the repaired blades require heavy machining toremove extra material followed by polishing to achieve a target surfacefinish. Notably, such machining and polishing processes are performed ona single blade at a time, are labor intensive and tedious, and result inlarge overall labor costs for a single repair.

Alternatively, other direct-energy-deposition (DED) methods may be usedfor blade repair, e.g., such as cold spray, which directs high-speedmetal powders to bombard the target or base component such that thepowders deform and deposit on the base component. However, none of theseDED methods are suitable for batch processing or for repairing a largenumber of components in a time-efficient manner, thus providing littleor no business value.

Accordingly, it would be desirable to provide improved system and methodfor repairing or rebuilding serviced components. More particularly,additive manufacturing machines and systems for quickly and effectivelyrebuilding or repairing worn compressor blades would be particularlydesirable.

BRIEF DESCRIPTION

Aspects and advantages will be set forth in part in the followingdescription, or may be obvious from the description, or may be learnedthrough practicing the presently disclosed subject matter.

In one aspect, the present disclosure embraces methods of generating aCAD model that includes an extension segment conforming to aworkpiece-interface. An exemplary method may include determining in alibrary-CAD model, a nominal model-interface traversing a nominal modelcorresponding to a workpiece, comparing the nominal model-interface ofthe library-CAD model to a digital representation of aworkpiece-interface of the workpiece, with the digital representationhaving been obtained using a vision system that has a field of viewincluding the workpiece-interface, and generating a model of anextension segment based at least in part on the nominal model-interface,with the model of the extension segment configured to be additivelyprinted on the workpiece-interface of the workpiece.

In another aspect, the present disclosure embraces additivemanufacturing systems. An exemplary additive manufacturing system mayinclude a controller operably coupled to a vision system and an additivemanufacturing machine. The controller may include one or more computerreadable medium and one or more processors. The one or more computerreadable medium may include computer-executable instructions, which,when executed by the one or more processors, causes the additivemanufacturing system to generate a CAD model that includes an extensionsegment conforming to a workpiece-interface.

By way of example, an additive manufacturing system may be configured todetermine in a library-CAD model, a nominal model-interface traversing anominal model corresponding to a workpiece. An additive manufacturingsystem may also be configured to compare the nominal model-interface ofthe library-CAD model to a digital representation of aworkpiece-interface of the workpiece, with the digital representationhaving been obtained using a vision system that has a field of viewincluding the workpiece-interface. Further, an additive manufacturingsystem may be configured to generate a model of an extension segmentbased at least in part on the nominal model-interface, with the model ofthe extension segment configured to be additively printed on theworkpiece-interface of the workpiece.

In yet another aspect, the present disclosure embraces computer readablemedium comprising computer-executable instructions, which, when executedby one or more processors of an additive manufacturing system, cause theadditive manufacturing system to generate a CAD model that includes anextension segment conforming to a workpiece-interface.

Exemplary computer readable medium may include computer-executableinstructions configured to cause an additive manufacturing system todetermine in a library-CAD model, a nominal model-interface traversing anominal model corresponding to a workpiece. Exemplary computer readablemedium may also include computer-executable instructions configured tocause an additive manufacturing system to compare the nominalmodel-interface of the library-CAD model to a digital representation ofa workpiece-interface of the workpiece, with the digital representationhaving been obtained using a vision system that has a field of viewincluding the workpiece-interface. Further, exemplary computer readablemedium may also include computer-executable instructions configured tocause an additive manufacturing system to generate a model of anextension segment based at least in part on the nominal model-interface,with the model of the extension segment configured to be additivelyprinted on the workpiece-interface of the workpiece.

These and other features, aspects and advantages will become betterunderstood with reference to the following description and appendedclaims. The accompanying drawings, which are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments and, together with the description, serve to explain certainprinciples of the presently disclosed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure, including the best mode thereof,directed to one of ordinary skill in the art, is set forth in thespecification, which makes reference to the appended Figures, in which:

FIGS. 1A and 1B schematically depict exemplary additive manufacturingsystems;

FIG. 2A schematically depicts an exemplary workpiece-assembly thatincludes a plurality of workpieces secured to a build plate;

FIG. 2B schematically depicts the exemplary workpiece-assembly of FIG.2A, with a plurality of components by additively printing extensionsegments the plurality of workpieces secured to the build plate;

FIGS. 3A and 3B respectively depict a plurality of workpieces misalignedwith a build plane, and a recoater consequently failing to successfullyapply a uniform layer of powder across the build plane;

FIGS. 3C and 3D respectively depict a plurality of workpieces alignedwith a build plane, and a recoater successfully applying a uniform layerof powder across the build plane;

FIG. 4 shows a flowchart depicting an exemplary method of additivelyprinting an extension segment on a workpiece-interface of a workpiece;

FIGS. 5A and 5B schematically depicts an exemplary workpiece before andafter subjecting the workpiece to a subtractive modification,respectively;

FIG. 5C schematically depicts an exemplary component formed byadditively printing an extension segment on the workpiece depicted inFIG. 5B;

FIG. 6A schematically depicts an exemplary digital representation of afield of view that includes a workpiece, captured using a vision system;

FIG. 6B schematically depicts an exemplary digital representation of oneor more fields of view that includes a plurality of workpieces, capturedusing the vision system;

FIG. 7A shows a flowchart depicting an exemplary method of determining aworkpiece, a workpiece-interface, and/or a workpiece-interfaceperimeter;

FIG. 7B shows a flowchart depicting an exemplary method of generating aprint command;

FIG. 8A schematically depicts an exemplary extension segment-CAD modelthat include a model of a plurality of extension segments;

FIG. 8B schematically depicts an exemplary library-CAD model thatincludes a nominal model of a plurality of nominal workpieces;

FIGS. 9A and 9B show a flowchart depicting an exemplary method ofgenerating an extension segment-CAD model;

FIGS. 10A-10D schematically depict exemplary transforming operationswhich may be performed so as to conform a nominal model-interface to adigital representation of a workpiece-interface, such as in theexemplary method depicted in FIGS. 9A and 9B;

FIG. 11A schematically depicts an exemplary nominal model, such as froma library-CAD model;

FIG. 11B schematically depicts an exemplary model of an extensionsegment, such as in an extension segment-CAD model;

FIGS. 12A-12D show flowcharts depicting exemplary methods of extending amodel-interface which may be performed so as to define a model of anextension segment extending in the z-direction from a model-interface toa nominal extended-plane, such as in the exemplary method depicted inFIGS. 9A and 9B;

FIG. 13 schematically depicts an exemplary print command for additivelyprinting a slice of a plurality of extension segments;

FIG. 14 schematically depicts an exemplary an exemplary calibration-CADmodel;

FIG. 15 schematically depicts an exemplary calibration surface thatincludes a plurality of printed calibration marks that were printedusing an additive manufacturing machine;

FIG. 16 schematically depicts an exemplary digital representation of afield of view that includes a plurality of calibration marks having beenobtained using a vision system;

FIG. 17 schematically depicts an exemplary comparison table illustratingan exemplary comparison of respective ones of a plurality of digitallyrepresented calibration marks to corresponding respective ones of aplurality of model calibration marks;

FIG. 18A schematically depicts an exemplary digital representation of aworkpiece-interface obtained from a vision system before calibration andafter calibration, such as for a calibration adjustment applied to thevision system;

FIG. 18B schematically depicts an exemplary location of an extensionsegment additively printed using an additive manufacturing machinebefore calibration and after calibration, such as for a calibrationadjustment applied to the additive manufacturing machine;

FIG. 18C schematically depicts an exemplary location of a model of anextension segment in an extension-segment CAD model before calibrationand after calibration, such as for a calibration adjustment applied tothe extension-segment CAD model;

FIG. 19 shows a flowchart depicting an exemplary method of calibratingan additive manufacturing system; and

FIG. 20 shows a block diagram depicting an exemplary control system ofan additive manufacturing system;

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to exemplary embodiments of thepresently disclosed subject matter, one or more examples of which areillustrated in the drawings. Each example is provided by way ofexplanation and should not be interpreted as limiting the presentdisclosure. In fact, it will be apparent to those skilled in the artthat various modifications and variations can be made in the presentdisclosure without departing from the scope or spirit of the presentdisclosure. For instance, features illustrated or described as part ofone embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present disclosurecovers such modifications and variations as come within the scope of theappended claims and their equivalents.

It is understood that terms such as “top”, “bottom”, “outward”,“inward”, and the like are words of convenience and are not to beconstrued as limiting terms. As used herein, the terms “first”,“second”, and “third” may be used interchangeably to distinguish onecomponent from another and are not intended to signify location orimportance of the individual components. The terms “a” and “an” do notdenote a limitation of quantity, but rather denote the presence of atleast one of the referenced item.

Here and throughout the specification and claims, range limitations arecombined and interchanged, and such ranges are identified and includeall the sub-ranges contained therein unless context or languageindicates otherwise. For example, all ranges disclosed herein areinclusive of the endpoints, and the endpoints are independentlycombinable with each other.

Approximating language, as used herein throughout the specification andclaims, is applied to modify any quantitative representation that couldpermissibly vary without resulting in a change in the basic function towhich it is related. Accordingly, a value modified by a term or terms,such as “about”, “approximately”, and “substantially”, are not to belimited to the precise value specified. In at least some instances, theapproximating language may correspond to the precision of an instrumentfor measuring the value, or the precision of the methods or machines forconstructing or manufacturing the components and/or systems.

As described in detail below, exemplary embodiments of the presentsubject matter involve the use of additive manufacturing machines ormethods. As used herein, the terms “additively manufactured” or“additive manufacturing techniques or processes” refer generally tomanufacturing processes wherein successive layers of material(s) areprovided on each other to “build-up,” layer-by-layer, athree-dimensional component. The successive layers generally fusetogether to form a monolithic component which may have a variety ofintegral sub-components.

As used herein, the term “near net shape” refers to an additivelyprinted feature that has an as-printed shape that is very close to thefinal “net” shape. A near net shape component may undergo surfacefinishing such as polishing, buffing, and the like, but does not requireheaving machining so as to achieve a final “net” shape. By way ofexample, a near net shape may differ from a final net shape by about1,500 microns or less, such as about 1,000 μm or less, such as about 500μm or less, such as about 250 μm or less, such as about 150 μm or less,such as about 100 μm or less, such as about 50 μm or less, or such asabout 25 μm or less.

Although additive manufacturing technology is described herein asenabling fabrication of complex objects by building objectspoint-by-point, layer-by-layer, typically in a vertical direction, othermethods of fabrication are possible and within the scope of the presentsubject matter. For example, although the discussion herein refers tothe addition of material to form successive layers, one skilled in theart will appreciate that the methods and structures disclosed herein maybe practiced with any additive manufacturing technique or manufacturingtechnology. For example, embodiments of the present invention may uselayer-additive processes, layer-subtractive processes, or hybridprocesses.

Suitable additive manufacturing techniques in accordance with thepresent disclosure include, for example, Fused Deposition Modeling(FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjetsand laserjets, Sterolithography (SLA), Direct Selective Laser Sintering(DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM),Laser Engineered Net Shaping (LENS), Laser Net Shape Manufacturing(LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP),Direct Selective Laser Melting (DSLM), Selective Laser Melting (SLM),Direct Metal Laser Melting (DMLM), and other known processes.

In addition to using a direct metal laser sintering (DMLS) or directmetal laser melting (DMLM) process where an energy source is used toselectively sinter or melt portions of a layer of powder, it should beappreciated that according to alternative embodiments, the additivemanufacturing process may be a “binder jetting” process. In this regard,binder jetting involves successively depositing layers of additivepowder in a similar manner as described above. However, instead of usingan energy source to generate an energy beam to selectively melt or fusethe additive powders, binder jetting involves selectively depositing aliquid binding agent onto each layer of powder. The liquid binding agentmay be, for example, a photo-curable polymer or another liquid bondingagent. Other suitable additive manufacturing methods and variants areintended to be within the scope of the present subject matter.

The additive manufacturing processes described herein may be used forforming components using any suitable material. For example, thematerial may be plastic, metal, concrete, ceramic, polymer, epoxy,photopolymer resin, or any other suitable material that may be in solid,liquid, powder, sheet material, wire, or any other suitable form. Morespecifically, according to exemplary embodiments of the present subjectmatter, the additively manufactured components described herein may beformed in part, in whole, or in some combination of materials includingbut not limited to pure metals, nickel alloys, chrome alloys, titanium,titanium alloys, magnesium, magnesium alloys, aluminum, aluminum alloys,iron, iron alloys, stainless steel, and nickel or cobalt basedsuperalloys (e.g., those available under the name Inconel® availablefrom Special Metals Corporation). These materials are examples ofmaterials suitable for use in the additive manufacturing processesdescribed herein and may be generally referred to as “additivematerials.”

In addition, one skilled in the art will appreciate that a variety ofmaterials and methods for bonding those materials may be used and arecontemplated as within the scope of the present disclosure. As usedherein, references to “fusing” may refer to any suitable process forcreating a bonded layer of any of the above materials. For example, ifan object is made from polymer, fusing may refer to creating a thermosetbond between polymer materials. If the object is epoxy, the bond may beformed by a crosslinking process. If the material is ceramic, the bondmay be formed by a sintering process. If the material is powdered metal,the bond may be formed by a melting or sintering process. One skilled inthe art will appreciate that other methods of fusing materials to make acomponent by additive manufacturing are possible, and the presentlydisclosed subject matter may be practiced with those methods.

In addition, the additive manufacturing process disclosed herein allowsa single component to be formed from multiple materials. Thus, thecomponents described herein may be formed from any suitable mixtures ofthe above materials. For example, a component may include multiplelayers, segments, or parts that are formed using different materials,processes, and/or on different additive manufacturing machines. In thismanner, components may be constructed which have different materials andmaterial properties for meeting the demands of any particularapplication. In addition, although the components described herein areconstructed entirely by additive manufacturing processes, it should beappreciated that in alternate embodiments, all or a portion of thesecomponents may be formed via casting, machining, and/or any othersuitable manufacturing process. Indeed, any suitable combination ofmaterials and manufacturing methods may be used to form thesecomponents.

An exemplary additive manufacturing process will now be described.Additive manufacturing processes fabricate components usingthree-dimensional (3D) information, for example a three-dimensionalcomputer model, of the component. Accordingly, a three-dimensionaldesign model of the component may be defined prior to manufacturing. Inthis regard, a model or prototype of the component may be scanned todetermine the three-dimensional information of the component. As anotherexample, a model of the component may be constructed using a suitablecomputer aided design (CAD) program to define the three-dimensionaldesign model of the component.

The design model may include 3D numeric coordinates of the entireconfiguration of the component including both external and internalsurfaces of the component. For example, the design model may define thebody, the surface, and/or internal passageways such as openings, supportstructures, etc. In one exemplary embodiment, the three-dimensionaldesign model is converted into a plurality of slices or segments, e.g.,along a central (e.g., vertical) axis of the component or any othersuitable axis. Each slice may define a thin cross section of thecomponent for a predetermined height of the slice. The plurality ofsuccessive cross-sectional slices together form the 3D component. Thecomponent is then “built-up” slice-by-slice, or layer-by-layer, untilfinished.

In this manner, the components described herein may be fabricated usingthe additive process, or more specifically each layer is successivelyformed, e.g., by fusing or polymerizing a plastic using laser energy orheat or by sintering or melting metal powder. For example, a particulartype of additive manufacturing process may use an energy beam, forexample, an electron beam or electromagnetic radiation such as a laserbeam, to sinter or melt a powder material. Any suitable laser and laserparameters may be used, including considerations with respect to power,laser beam spot size, and scanning velocity. The build material may beformed by any suitable powder or material selected for enhancedstrength, durability, and useful life, particularly at hightemperatures.

Each successive layer may be, for example, between about 10 μm and 200μm, although the thickness may be selected based on any number ofparameters and may be any suitable size according to alternativeembodiments. Therefore, utilizing the additive formation methodsdescribed above, the components described herein may have cross sectionsas thin as one thickness of an associated powder layer, e.g., 10 μm,utilized during the additive formation process.

In addition, utilizing an additive process, the surface finish andfeatures of the components may vary as need depending on theapplication. For example, the surface finish may be adjusted (e.g., madesmoother or rougher) by selecting appropriate laser scan parameters(e.g., laser power, scan speed, laser focal spot size, etc.) during theadditive process, especially in the periphery of a cross-sectional layerwhich corresponds to the part surface. For example, a rougher finish maybe achieved by increasing laser scan speed or decreasing the size of themelt pool formed, and a smoother finish may be achieved by decreasinglaser scan speed or increasing the size of the melt pool formed. Thescanning pattern and/or laser power can also be changed to change thesurface finish in a selected area.

After fabrication of the component is complete, various post-processingprocedures may be applied to the component. For example, post processingprocedures may include removal of excess powder by, for example, blowingor vacuuming. Other post processing procedures may include a stressrelief process. Additionally, thermal, mechanical, and/or chemical postprocessing procedures can be used to finish the part to achieve adesired strength, surface finish, and other component properties orfeatures.

Notably, in exemplary embodiments, several aspects and features of thepresent subject matter were previously not possible due to manufacturingrestraints. However, the present inventors have advantageously utilizedcurrent advances in additive manufacturing techniques to improve variouscomponents and the method of additively manufacturing such components.While the present disclosure is not limited to the use of additivemanufacturing to form these components generally, additive manufacturingdoes provide a variety of manufacturing advantages, including ease ofmanufacturing, reduced cost, greater accuracy, etc.

Also, the additive manufacturing methods described above enable muchmore complex and intricate shapes and contours of the componentsdescribed herein to be formed with a very high level of precision. Forexample, such components may include thin additively manufacturedlayers, cross sectional features, and component contours. In addition,the additive manufacturing process enables the manufacture of a singlecomponent having different materials such that different portions of thecomponent may exhibit different performance characteristics. Thesuccessive, additive nature of the manufacturing process enables theconstruction of these novel features. As a result, components formedusing the methods described herein may exhibit improved performance andreliability.

The present disclosure generally provides additive manufacturingmachines, systems, and methods configured to additively print onpre-existing workpieces. The pre-existing workpieces may include newworkpieces as well as workpieces being repaired, rebuilt, or upgraded.The presently disclosed additive manufacturing systems and methodsutilize a vision system to capture digital representations of one ormore workpieces situated in a field of view, which may be in the form ofdigital images or the like. The shape and location of each workpiece maybe determined using the vision system and print commands may begenerated based at least in part on the digital representation of theone or more workpieces. The print commands may be configured to cause anadditive manufacturing machine to additively print an extension segmentdirectly on each of the one or more workpieces.

The workpieces may include a workpiece-interface, which refers to asurface upon which an additive manufacturing machine may additivelyprint an extension segment. For some workpieces, the workpiece-interfacemay include a surface that has undergone pre-processing in preparationfor additively printing. For example, a surface may be machined, ground,brushed, etched, polished, or otherwise substantively modified so as toprovide a workpiece-interface. Such subtractive modification may removeat least a portion of a surface that has been worn or damaged, and/ormay improve bonding between the workpiece and the additively printedmaterial. In the case of previously used components, such as compressorblades or turbine blades, the surface may be damaged or worn to somedegree, including artifacts such as microcracks, pits, abrasions,defects, foreign material, depositions, imperfections, and the like. Thesubtractive modification process may remove such damage or wear toprovide a workpiece with a workpiece-interface that is ready foradditive printing.

One exemplary type of workpiece includes airfoils for a turbomachine,such as compressor blades and/or turbine blades. A typical turbomachineincludes one or more compressor sections, each of which may includemultiple compressor stages, and one or more turbine sections, each ofwhich may include multiple turbine stages. The compressor sections andturbine sections are typically oriented along an axis of rotation andrespectively include a series of airfoils disposed circumferentiallyaround the respective stage and circumferentially surrounded by ashroud.

Typically, the nature and extent of damage or wear to a set of bladesremoved from a turbomachine for repair or rebuild varies from blade toblade. As a result, the amount of material that may need to be removedduring a subtractive modification process so as to prepare aworkpiece-interface may vary from one blade to the next. Additionally,some of the blades may be deformed from their original net shape throughexposure to high stresses and temperatures and/or through damage fromrubbing on shrouds and so forth. As a result, each individual blade maydiffer from its original net shape in varying degrees from one blade tothe next.

Additionally, the size and shape of the airfoils may differ from onestage to the next, and the tips of the airfoils provides a relativelysmall workpiece-interface. As an example, exemplary high-pressurecompressor blades may be about 1 to 2 inches tall and may have a bladetip with a cross-sectional width of about 0.5 mm to about 5 mm, whichprovides for a particularly small workpiece-interface, which providesfor a particularly small workpiece-interface. Other exemplaryhigh-pressure compressor blades, as well as low-pressure compressorblades and blades from a turbine section (e.g., high-pressure turbineblades and low-pressure turbine blades) may be somewhat larger, such asup to about 10 inches tall, but nevertheless provide for a smallworkpiece-interface.

This variability from one workpiece to the next, including variabilityas to differences from original net shape, differing amounts ofsubtractive modification, and/or differences in size and shape, presentsseveral key challenges in additively printing on the workpiece-interfaceof such workpieces, which are addressed by the present disclosure. Inparticular, the present disclosure provides for additively printingextension segments on the workpiece-interface of respective workpieceswith sufficient precision and accuracy so as to provide near net shapecomponents even though the respective workpieces may differ from oneanother because of one or more of such sources of variability.

In some embodiments, the present disclosure provides systems and methodsof securing workpieces to a build plate and/or within a build chamber sothat an additive manufacturing machine or system may additively printonto the workpiece-interfaces of the respective workpieces as part of acommon build even when the workpieces have different sizes or shapes.For example, the present disclosure provides build plates that includeone or more biasing members configured to align the workpiece-interfaceswith one another, and one or more clamping mechanisms which operate tosecure the workpieces to the build plate. The workpieces may be securedto the build plate at locations which may be identified by registrationpoints mapped to a coordinate system that may be utilized by theadditive manufacturing system to locate the workpieces and/or theirworkpiece-interfaces.

In some embodiments, the present disclosure provides systems and methodsof determining or generating a CAD model that includes a model of one ormore extension segments, such as an extension segment-CAD model, thatconform to the location and shape of one or more correspondingworkpieces upon which the extension segments are to be additivelyprinted. Such an extension segment-CAD model may be utilized to generateprint commands for an additive manufacturing machine, allowing theadditive manufacturing machine to additively print extension segmentsonto workpiece-interfaces with sufficient precision or accuracy toprovide near net shape components.

The present disclosure provides for determining and/or generating anextension segment CAD model, for example, from a library-CAD model thatincludes a nominal model of one or more nominal workpieces, components,or extension segments. The library-CAD model may be selected from alibrary of CAD models based at least in part on a digital representationof a field of view of one or more workpiece-interfaces obtained from thevision system. A nominal model-interface traversing a nominal model maybe determined in a library-CAD model, and a model of an extensionsegment may be selected and/or generated based at least in part on acomparison of the nominal model-interface to a digital representation ofa workpiece-interface. A model of one or more extension segments may beoutput to an extension segment-CAD model and print commands for theadditive manufacturing machine may be generated using the extensionsegment-CAD model.

In some embodiments, generating the model of an extension segment mayinclude extracting the nominal model-interface from the nominal model,transforming the nominal model-interface based at least in part on thecomparison to the digital representation of the workpiece-interface,and/or extending the transformed model-interface so as to provide themodel of the extension segment. Additionally, or in the alternative, amodel of an extension segment may be generated from a three-dimensionalportion of a nominal model, which may include transforming suchthree-dimensional portion so as to provide a model of an extensionsegment conforming to the digital representation of theworkpiece-interface.

The present disclosure also provides for systems and methods ofperforming calibration adjustments so as to prevent or mitigatediscrepancies, biases, misalignments, calibration errors, or the likewhich may otherwise arise from time to time as between one or moreaspects of the additive manufacturing system. Such calibrationadjustments may be configured to address potential discrepancies,biases, misalignments, calibration errors, or the like between a visionsystem and an additive manufacturing machine, between a vision systemand one or more CAD models generated, or between one or more CAD modelsand an additive manufacturing machine, as well as combinations of these.

When additively printing an extension segment on a workpiece-interface,misalignment between the workpiece and the extension segment may resultin a failed build or a defective component. Previous additivemanufacturing system may exhibit systematic bias in the mapping betweenthe toolpath coordinates and the coordinates of a CAD model. Suchsystematic bias may cause additively printed components to be shiftedglobally, which may have been of little consequence for previousadditive manufacturing systems. However, the present disclosure providesfor near net shape components, such that the extension segment conformsto the location and shape of the workpiece-interface of the workpiece.To provide such near net shape components, not only is the precision ofthe additive manufacturing tool of importance, but it is also ofimportance that the location and shape of the workpieces andcorresponding extension segments be accurately and precisely alignedwith one another.

In some embodiments, the additive material used for the extensionsegments may differ from the material of the workpieces. Differences inmaterial may provide for different properties or performancecharacteristics of the extension segments relative to the workpieces,including enhanced wear resistance, improved hardness, strength, and/orductility. New or unused components may be additively manufactured orupgraded in accordance with the present disclosure so as to provide anextension segment with a material that differs from that of theworkpiece. For example, airfoils such as compressor blades or turbineblades may be upgraded with blade tips formed of a superior performingmaterial. Likewise, damaged or worn components may be repaired orrebuild using a material that differs from that of the workpiece, forexample, using a superior performing material.

Exemplary embodiments of the present disclosure will now be described infurther detail. Exemplary embodiments of an additive manufacturingsystem 100 are shown in FIGS. 1A and 1B. An exemplary additivemanufacturing system 100 includes a vision system 102, an additivemanufacturing machine 104, and a control system 106 operably configuredto control the vision system 102 and/or the additive manufacturingmachine 104. The vision system 102 and the additive manufacturingmachine 104 may be provided as a single, integrated unit or as separatestand-alone units. The vision system 102 and the additive manufacturingmachine 104 may be operably coupled with one another via a communicationinterface utilizing wired or wireless communication lines, which mayprovide a direct connection between the vision system 102 and theadditive manufacturing machine 104. The control system 106 may includeone or more control systems 106. For example, a single control system106 may be operably configured to control operations of the visionsystem 102 and the additive manufacturing machine 104, or separatecontrol systems 106 may be operably configured to respectively controlthe vision system 102 and the additive manufacturing machine 104. Acontrol system 106 may be realized as part of the vision system 102, aspart of the additive manufacturing machine 104, and/or as a stand-aloneunit provided separately from the vision system 102 and/or the additivemanufacturing machine 104. A control system 106 may be operably coupledwith the vision system 102 and/or the additive manufacturing machine 104via a communication interface utilizing wired or wireless communicationlines, which may provide a direct connection between the control system106 and the vision system 102 and/or between the control system 106 andthe additive manufacturing machine 104. An exemplary additivemanufacturing system 100 may optionally include a user interface 108and/or a management system 110.

In some embodiments, a first control system 106 may determine anextension segment-CAD model, generate one or more print commands basedat least in part on the extension segment-CAD model, and/or transmit theone or more print commands to a second control system 106, and thesecond control system 106 may cause the additive manufacturing machine104 to additively print the extension segments based at least in part onthe print commands. The first control system 106 may be realized as partof a vision system 102, and/or the second control system 106 may berealized as part of the additive manufacturing machine 104.Alternatively, or in addition, the first control system 106 and/or thesecond control system 106 may be realized stand-alone units separatefrom the vision system 102 and/or the additive manufacturing machine104.

In some embodiments, a first control system 106 may determine andtransmit an extension segment-CAD model to a second control system 106,the second control system 106 may slice the extension segment-CAD modelso as to generate one or more print commands and concurrently orsubsequently transmit the one or more print commands to a third controlsystem 106, and the third control system may cause the additivemanufacturing machine 104 to additively print the extension segmentsbased at least in part on the one or more print commands. The firstcontrol system 106 may be realized as part of a vision system 102, thesecond control system 106 may be realized as a stand-alone unit, and thethird control system 106 may be realized as part of the additivemanufacturing machine 104. Alternatively, or in addition, the firstcontrol system 106 and/or the second control system 106 may be realizedas stand-alone units separate from the vision system 102 and/or theadditive manufacturing machine 104.

The vision system 102 may include any suitable camera or cameras 112 orother machine vision device that may be operably configured to obtainimage data that includes a digital representation of one or more fieldsof view 114. Such a digital representation may sometimes be referred toas a digital image or an image; however, it will be appreciated that thepresent disclosure may be practiced without rendering such a digitalrepresentation in human-visible form. Nevertheless, in some embodiments,a human-visible image corresponding to a field of view 114 may bedisplayed on the user interface 108 based at least in part on such adigital representation of one or more fields of view 114.

The vision system 102 allows the additive manufacturing system 100 toobtain information pertaining to one or more workpieces 116 onto whichone or more extension segments may be respectively additively printed.In particular, the vision system 102 allows the one or more workpieces116 to be located and defined so that the additive manufacturing machine104 may be instructed to print one or more extension segments on acorresponding one or more workpieces 116 with suitably high accuracy andprecision. The one or more workpieces 116 may be secured to a buildplate 118 with a workpiece-interface (e.g. a top surface) 120 of therespective workpieces 116 aligned to a build plane 122.

The one or more cameras 112 of the vision system 102 may be configuredto obtain two-dimensional or three-dimensional image data, including atwo-dimensional digital representation of a field of view 114 and/or athree-dimensional digital representation of a field of view 114.Alignment of the workpiece-interfaces 120 with the build plane 122allows the one or more cameras 112 to obtain higher quality images. Forexample, the one or more cameras 112 may have a focal length adjusted oradjustable to the build plane 122. With the workpiece-interface 120 ofone or more workpieces 116 aligned to the build plane 122, the one ormore cameras may readily obtain digital images of theworkpiece-interfaces 120. The one or more cameras 112 may include afield of view 114 that that encompasses all or a portion of the one ormore workpieces 116 secured to the build plate 118. For example, asingle field of view 114 may be wide enough to encompass a plurality ofworkpieces 116, such as each of a plurality of workpieces secured to abuild plate 118. Alternatively, a field of view 114 may more narrowlyfocus on an individual workpiece 116 such that digital representationsof respective workpieces 116 are obtained separately. It will beappreciated that separately obtained digital images may be stitchedtogether to obtain a digital representation of a plurality of workpieces116. In some embodiments, the camera 112 may include a collimated lensconfigured to provide a flat focal plane, such that workpieces orportions thereof located towards the periphery of the field of view 114are not distorted. Additionally, or in the alternative, the visionsystem 102 may utilize a distortion correction algorithm to address anysuch distortion.

Image data obtained by the vision system 102, including a digitalrepresentation of one or more workpieces 116 may be transmitted to thecontrol system 106. The control system 106 may be configured todetermine a workpiece-interface 120 of each of a plurality of workpieces116 from one or more digital representations of one or more fields ofview 114 having been captured by the vision system 102, and thendetermine one or more coordinates of the workpiece-interface 120 ofrespective ones of the plurality of workpieces 116. Based on the one ormore digital representations, the control system 106 may generate one ormore print commands, which may be transmitted to an additivemanufacturing machine 104 such that the additive manufacturing machine104 may additively print a plurality of extension segments on respectiveones of the plurality of workpieces 116. The one or more print commandsmay be configured to additively print a plurality of extension segmentswith each respective one of the plurality of extension segments beinglocated on the workpiece-interface 120 of a corresponding workpiece 116.

The additive manufacturing machine 104 may utilize any desired additivemanufacturing technology. In an exemplary embodiment, the additivemanufacturing machine may utilize a powder bed fusion (PBF) technology,such as direct metal laser melting (DMLM), electron beam melting (EBM),selective laser melting (SLM), directed metal laser sintering (DMLS), orselective laser sintering (SLS). The additive manufacturing machine 104may include any such additive manufacturing technology, or any othersuitable additive manufacturing technology may also be used. By way ofexample, using a powder bed fusion technology, respective ones of aplurality of extension segments may be additively printed oncorresponding respective ones of a plurality of workpieces 116 in alayer-by-layer manner by melting or fusing a layer of powder material tothe workpiece-interface 120. In some embodiments, a component may beadditively printed by melting or fusing a single layer of poweredmaterial to the workpiece-interface 120. Additionally, or in thealternative, subsequent layers of powder material may be sequentiallymelted or fused to one another.

Still referring to FIGS. 1A and 1B, an exemplary additive manufacturingmachine 104 includes a powder supply chamber 124 that contains a supplyof powder 126, and a build chamber 128. A build plate 118 having one ormore workpieces 116 secured thereto may be positioned in the buildchamber 128, where the workpieces 116 may be additively printed in alayer-by-layer manner. The powder supply chamber 124 includes a powderpiston 130 which elevates a powder floor 132 during operation of thesystem 100. As the powder floor 132 elevates, a portion of the powder126 is forced out of the powder supply chamber 124.

A recoater 134, such as a roller or a blade, pushes some of the powder126 across a work surface 136 and onto a build platform 138. The buildplate 118 may be secured to the build platform 138 with a chuck system140 in a manner configured to position the build plate 118 on the buildplatform 138 and/or within the build chamber 128 with sufficiently highaccuracy and precision. The workpieces 116 may be secured to the buildplate 118 prior to securing the build plate 118 to the build platform138. The recoater 134 fills the build chamber 128 with powder 126 andthen sequentially distributes thin layers of powder 126 across a buildplane 122 near the top of the workpieces 116 to additively printsequential layers of the workpieces 116. For example, the thin layers ofpowder 126 may be about 10 to 100 microns thick, such as about 20 to 80μm thick, such as about 40 to 60 μm thick, or such as about 20 to 50 μmthick, or such as about 10 to 30 μm thick. The build plane 122represents a plane corresponding to a next layer of the workpieces 116to be formed from the powder 126.

To form a layer of an extension segment on the workpiece 116 (e.g., aninterface layer or a subsequent layer), an energy source 142 directs anenergy beam 144 such as a laser or an electron beam onto the thin layerof powder 126 along the build plane 122 to melt or fuse the powder 126to the top of the workpieces 116 (e.g., to melt or fuse a layer to theworkpiece-interfaces 120 and/or melt or fuse subsequent layers thereto).A scanner 146 controls the path of the beam so as to melt or fuse onlythe portions of the powder 126 layer that are to become melted or fusedto the workpieces 116. Typically, with a DMLM, EBM, or SLM system, thepowder 126 is fully melted, with respective layers being melted orre-melted with respective passes of the energy beam 144. Conversely,with DMLS, or SLS systems, layers of powder 126 are sintered, fusingparticles of powder 126 with one another generally without reaching themelting point of the powder 126. After a layer of powder 126 is meltedor fused to the workpieces 116, a build piston 148 gradually lowers thebuild platform 138 by an increment, defining a next build plane 122 fora next layer of powder 126 and the recoater 134 to distributes the nextlayer of powder 126 across the build plane 122. Sequential layers ofpowder 126 may be melted or fused to the workpieces 116 in this manneruntil the additive printing process is complete.

Referring to FIGS. 2A and 2B, an exemplary workpiece-assembly 200 thatincludes a plurality of workpieces 116 secured to a build plate 118 isshown. The build plate 118 may be configured to align the workpieces 116to respective registration points 202. The registration points 202 maybe mapped to a coordinate system. FIG. 2A shows a workpiece-assembly 200that includes a plurality of workpieces 116 secured to a build plate118. The arrangement depicted in FIG. 2A reflects a point in time priorto additively printing extension segments onto the workpiece-interfaces120. FIG. 2B shows the workpiece-assembly 200 of FIG. 2A but reflectinga point in time after an additive printing process. As shown in FIG. 2B,a plurality of components 204 are secured to the build plate 118, whichwere formed during the additive printing process by additively printingrespective ones of a plurality of extension segments 206 onto respectiveones of the plurality of workpieces 116.

The build plate 118 and/or workpiece-assembly 200 shown in FIGS. 2A and2B may be used to facilitate additively printing an extension segment206 on a workpiece 116, including additively printing respective ones ofa plurality of extension segments 206 on respective ones of a pluralityof workpieces 116 as part of a single build. In some embodiments, abuild plate 118 may be configured to align the workpieces 116 torespective registration points 202 so as to facilitate image capture bythe vision system 102, so as to facilitate alignment of CAD models withthe workpieces 116 (e.g., so that extension segments 206 as defined by aCAD model may be properly additively printed on the workpieces 116),and/or so as to facilitate operability of the additive manufacturingmachine 104.

The workpiece-assembly 200 shown in FIGS. 2A and 2B may hold any numberof workpieces 116. As one example, the workpiece-assembly 200 shown mayhold up to 20 workpieces 116. As another example, a workpiece-assembly200 may be configured to hold from 2 to 100 workpieces 116, or more,such as from 2 to 20 workpieces 116, such as from 10 to 20 workpieces116, such as from 20 to 60 workpieces 116, such as from 25 to 75workpieces 116, such as from 40 to 50 workpieces 116, such as from 50 to100 workpieces 116, such as from 5 to 75 workpieces 116, such as from 75to 100 workpieces 116, such as at least 2 workpieces 116, such as atleast 10 workpieces 116, such as at least 20 workpieces 116, such as atleast 40 workpieces 116, such as at least 60 workpieces 116, or such asat least 80 workpieces 116.

In some embodiments, for example, when the workpieces 116 are airfoilssuch as compressor blades or turbine blades of a turbomachine, theworkpiece-assembly 200 may be configured to hold a number of blades thatcorresponds to the number of blades in one or more stages of thecompressor and/or turbine, as applicable. In this way, all of the bladesof a given one or more stages of a turbine and/or compressor may be kepttogether and extension segments 206 may be additively printed thereon inone single build. It will be appreciated that the workpiece-assembly 200and build plate 118 reflect one exemplary embodiment, which is providedby way of example and not to be limiting. Various other embodiments of aworkpiece-assembly 200 and/or build plate 118 are contemplated which mayalso allow for the workpieces 116 to be secured with suitablepositioning and alignment, all of which are within the spirit and scopeof the present disclosure.

The exemplary workpiece-assembly 200 shown in FIGS. 2A and 2B includes abuild plate 118 with one or more workpiece bays 208 disposed therein.Each of the one or more workpiece bays 208 may include one or moreworkpiece docks 210. The one or more workpiece bays 208 may additionallyinclude one or more clamping mechanisms 212 which operate to secure oneor more workpieces 116 to the build plate 118. The one or more workpiecedocks 210 may be configured to receive one or more workpiece shoes 214,and the one or more workpiece shoes 214 may be respectively configuredto receive a workpiece 116. The one or more clamping mechanisms 212 maybe configured to clamp the workpiece shoes 214 in position within thecorresponding workpiece docks 210.

A workpiece dock 210 and/or a workpiece shoe 214 may include one or morebiasing members (not shown) configured to exert a biasing force (e.g.,an upward or vertical biasing force) between the workpiece shoe 214 andthe build plate 118 such as the bottom of the workpiece dock 210. Thebiasing members may include one or more springs, one or more magnetpairs (e.g. permanent magnets or electromagnets), one or morepiezoelectric actuator, or the like operable to exert such a biasingforce. The biasing force exerted by the biasing members biases theworkpiece shoe 214 so as to allow the workpiece-interfaces 120 (e.g.,the top surfaces of the workpieces 116) to be aligned with one another.By way of example, an alignment plate (not shown) may be placed on topof the workpieces 116 so as to partially compress the biasing membersand bring the workpiece-interfaces 120 (e.g., the top surfaces of theworkpieces 116) into alignment with one another. In some embodiments,elevating blocks (not shown) may be placed between the build plate 118and the alignment plate (not shown) to assist in positioning thealignment plate on top of the workpieces 116 at a desired height. Withthe workpiece-interfaces 120 aligned with one another, the clampingmechanism 212 may be tightened so as to secure the workpieces 116 to thebuild plate 118.

As shown in FIGS. 3A and 3B, a misalignment of workpieces 116 from thebuild plane 122 may introduce printing failures. FIG. 3A shows aplurality of workpieces 116, including a first workpiece 300 situated inalignment with the build plane 122, a second workpiece 302 situatedbelow the build plane 122, and a third workpiece 304 situated above thebuild plane 122. When the recoater 134 distributes powder 126 across thebuild plane 122, the first workpiece 300 would generally be expected toreceive an appropriately thick layer of powder 126 across the topportion thereof. By contrast, the second workpiece 302 and the thirdworkpiece 304 illustrate misalignments from the build plane 122 whichmay likely cause printing failures. For example, the second workpiece302 may exhibit printing failures attributable to an overly thick layer306 of powder 126, such as insufficient bonding of the powder 126 layerto the second workpiece 302. Such insufficient bonding may be caused byincomplete melting of the powder 126 or the top layer (e.g., theworkpiece-interface 120) of the second workpiece 302, as well as voidsformed from gasses trapped within the layer that with adequate meltinggenerally would be eliminated. As another example, the third workpiece304 may exhibit printing failures attributable to the surface 308 of thethird workpiece 304 protruding above the build plane 122, such that therecoater 134 may skip over the protruding surface 308 of the thirdworkpiece 304 and/or such that the recoater 134 may become obstructed bythe third workpiece, damaging the recoater 134 or preventing therecoater 134 from moving past the protruding surface 308.

In some embodiments, even if a mis-aligned workpiece 116 does not causea total printing failure such as obstructing the recoater 134, themisalignment may cause variations in melting, dimensional inaccuracy,microhardness, tensile properties, and/or material density. Thesevariations may propagate as sequential layers are added to theworkpieces 116. Additionally, components 204 with such variations mayfail during operation, potentially causing damage to other equipmentincluding catastrophic failures. For example, if a compressor blade orturbine blade fails, the failure may damage other portions of theturbomachine potentially rendering the turbomachine immediatelyinoperable.

However, as shown in FIGS. 3C and 3D, the present disclosure provides abuild plate 118 and/or workpiece-assembly 200 configured to align thetop portions of a plurality of workpieces 116 with a build plane 122. Inan exemplary embodiment, the top portion of a workpiece 116 provides aworkpiece-interface 120, which workpiece-interface 120 may be preparedat least in part by performing a subtractive modification to theworkpiece 116. Such workpiece-interfaces 120 may include a surface, aplane, a tip, or the like generally corresponding to the highest ortallest portion of the workpiece 116 when loaded into the build plate118. With the top portions aligned, a plurality of extension segments206 may be additively printed on a corresponding plurality of workpieces116 together in a common build using a powder bed fusion process whileassuring that the recoater 134 may apply uniform layers of powder 126across each of the workpieces 116. In some embodiments, the build plate118 may be capable of aligning a plurality of workpieces 116 to a buildplane 122 within a tolerance of 100 microns or less, such as 80 μm orless, such as 60 μm or less, such as 40 μm or less, such as 20 μm orless, or such as 10 μm or less.

The alignment provided by the workpiece-assembly 200 may compensate fordifferences in the size of respective workpieces 116. Such differencesin size may be attributable to workpieces 116 having variations in sizearising from any source, including the workpieces 116 having a differentoriginal configuration, and/or the workpieces 116 having variations insize arising from a subtractive modification performed to prepare aworkpiece-interface 120 on the workpieces 116. In some embodiments, forexample, when the workpieces 116 are airfoils of a turbomachine, such ascompressor blades and/or turbine blades, such airfoils from differentstages of the turbomachine may secured within a workpiece-assembly 200with the respective workpiece-interfaces 120 (e.g., the top surfaces ofthe workpieces 116) aligned with one another even though the respectiveworkpieces 116 may have different sizes relative to one another.

Now referring to FIG. 4, an exemplary method 400 of additively printingan extension segment 206 on a workpiece-interface 120 of a workpiece 116will be described. The exemplary method may be performed by an additivemanufacturing system 100 as described herein, such as using a controlsystem 106 communicatively coupled to a vision system 102 and anadditive manufacturing machine 104. An exemplary method 400 includes, atstep 402, determining a workpiece-interface 120 from a digitalrepresentation of a field of view 114 having been captured by a visionsystem 102. Determining the workpiece 116 may include determining aworkpiece-interface 120. For example, the exemplary method may includedetermining a workpiece-interface 120 of each of a plurality ofworkpieces 116 from one or more digital representations of one or morefields of view 114 having been captured by a vision system 102.Determining the workpiece-interface 120 may include determining one ormore coordinates of the workpiece-interface 120, for example, ofrespective ones of the plurality of workpieces 116. The one or morefields of view 114 may include one or more workpieces situated inthree-dimensional space, such as a two-dimensional field of view 114 ora three-dimensional field of view 114. For example, the one or morefields of view 114 may include a two-dimensional or three-dimensionaltop view of one or more workpieces 116 individually and/or of aplurality of workpieces 116 collectively, such as a two-dimensional orthree-dimensional top view of the workpiece-interface 120 of one or moreworkpieces 116 individually and/or of a plurality of workpieces 116collectively.

In some embodiments, an exemplary method 400 may include, at step 404,obtaining a digital representation of a field of view 114 using a visionsystem 102, where the field of view 114 includes a workpiece-interface120. This may include obtaining one or more digital representations ofthe one or more fields 114 of view using the vision system 102.Alternatively, an exemplary method 400 may commence with one or moredigital representations already having been obtained from the visionsystem 102.

An exemplary method 400 additionally includes, at step 406, transmittingto an additive manufacturing machine 104, a print command configured toadditively print an extension segment 206 on a workpiece-interface 120,with the print command having been generated based at least in part onthe digital representation of the field of view 114. The print commandmay be configured to additively print the extension segment 206 on aworkpiece-interface 120. One or more print commands may be transmittedto the additive manufacturing machine 104, and the one or more printcommands may be configured to additively print a plurality of extensionsegments 206 with each respective one of the plurality of extensionsegments 206 being located on the workpiece-interface 120 of acorresponding respective one of the plurality of workpieces 116.

The one or more print commands may be generated based at least in parton the one or more digital representations of the one or more fields ofview 114. The exemplary method 400 may optionally include, at step 408,generating a print command based at least in part on a digitalrepresentation of a field of view 114 captured by the vision system 102.This may include generating one or more print commands based at least inpart on one or more digital representations of the one or more fields ofview 114 that include one or more workpieces 116 and/or one or moreworkpiece-interfaces 120 thereof. Alternatively, an exemplary method 400may be performed with one or more print commands already having beengenerated or having been generated separately, such as by the controlsystem 106 or otherwise.

An exemplary method 400 may additionally include, at step 410,additively printing an extension segment 206 on a workpiece-interface120 based at least in part on the print command. This may includeadditively printing respective ones of a plurality of extension segments206 on corresponding respective ones of a plurality of workpieces 116,such as on corresponding respective ones of a plurality ofworkpiece-interfaces 120 thereof. For example, the one or more printcommands may be configured to position respective ones of the pluralityof extension segments 206 on the workpiece-interface 120 ofcorresponding respective ones of the plurality of workpieces 116 basedat least in part on one or more coordinates of the respectiveworkpiece-interface 120.

The exemplary method 400 may be performed so as to provide a component204 by additively printing one or more extension segments 206 onto oneor more workpieces 116. In some embodiments, a plurality of workpieces116 may include a plurality of blades for a turbomachine, such ascompressor blades and/or turbine blades, and the corresponding pluralityof extension segments 206 may include a plurality blade tips. Thecomponents 204 may be additively printed in a layer-by-layer mannerusing an additive manufacturing machine 104. For example, the exemplarymethod 400 may include additively printing a first layer of a pluralityof extension segments 206 on the workpiece-interface 120 of respectiveones of the plurality of workpieces 116, followed by additively printinga second layer of the plurality of extension segments 206 on the firstlayer of the plurality of extension segments 206. The first layer may bean interface layer between the workpiece-interface 120 and the extensionsegment 206 to be additively printed thereon. The second layer may be asubsequent layer of the extension segment 206. In some embodiments, acomponent 204 may be additively printed by melting or fusing a singleinterface layer of powered material to the workpiece-interface 120.

Now referring to FIGS. 5A-5C, an exemplary workpiece 116 (FIGS. 5A and5B) and an exemplary component 204 (FIG. 5C) are shown. The exemplaryworkpiece 116 and component 204 may be an airfoil such as a compressorblade or a turbine blade, or any other workpiece 116 or component 204.As shown, the workpiece 116 and component 204 represent a high-pressurecompressor blade (HPC-blade) of a turbomachine. The workpiece 116 may bean originally fabricated workpiece, as well as a workpiece 116 beingrepaired, rebuilt, and so forth.

An exemplary method 400 may include subjecting workpieces 116 to asubtractive modification so as to provide a workpiece-interface 120thereon. This may include cutting, grinding, machining,electrical-discharge machining, brushing, etching, polishing, orotherwise substantively modifying a workpiece 116 so as to provide aworkpiece-interface 120 thereon. The subtractive modification mayinclude removing a subtraction portion 500 (FIG. 5A), so as to provide aworkpiece-interface 120 (FIG. 5B). The subtractive modification mayinclude removing at least a portion of a surface of the workpiece 116that has been worn or damaged. For example, as shown in FIG. 5A, theworkpiece 116 may include artifacts 502, such as microcracks, pits,abrasions, defects, foreign material, depositions, imperfections, andthe like. Such artifacts 502 may commonly appear on the top surface of acompressor or turbine blade as a result of the extreme conditions towhich such blades are subjected. The subtractive modification mayadditionally or alternatively be performed so as to improve bondingbetween the workpiece 116 and the extension segment 206.

When the workpieces 116 include airfoils for a turbomachine, such ascompressor blades and/or turbine blades, as shown in FIGS. 5A and 5B,the subtractive modification may include removing a tip portion of theairfoils, for example, to remove a worn or damaged area. Alternatively,in some embodiments, a component 204 may initially appear as shown inFIG. 5B, without requiring a subtractive modification, or withoutrequiring a substantial portion of the component 204 to be removedduring the subtractive modification. For example, the workpiece 116 maybe an intermediate workpiece 116 in an original fabrication process.

The amount of material removed during the subtractive modification mayvary depending on the nature of the workpiece 116, such as how muchmaterial needs to be subtracted so as to provide a workpiece-interface120 and/or to remove worn or damaged material. The amount of materialremoved may be limited to only a very thin surface layer when thesubtractive modification is intended to prepare a workpiece-interface120 without removing layers of more substantial thickness, or when wearor damage to a workpiece 116 is limited to a thin surface layer.Alternatively, the amount of material removed from a workpiece 116 mayinclude a majority of the workpiece 116, such as when the workpiece 116has larger cracks, breaks, or other damage penetrating deeper into theworkpiece 116.

In some embodiments, the amount of material removed may be from about 1micron to 1 centimeter, such as from about 1 μm to about 1,000 μm, suchas from about 1 μm to about 500 μm, such as from about 1 μm to about 100μm, such as from about 1 μm to about 25 μm, such as from about 100 μm toabout 500 μm, such as from about 500 μm to about 1,000 μm, such as fromabout 100 μm to about 5 mm, such as from about 1 mm to about 5 mm, suchas from about 5 mm to about 1 cm. In still further embodiments, theamount of material removed may be from about 1 centimeter to about 10centimeters, such as from about 1 cm to about 5 cm, such as from about 2cm to about 7 cm, such as from about 5 cm to about 10 cm.

Regardless of the nature of the workpiece 116, as shown in FIG. 5C, anear net shape component 204 may be formed by additively printing anextension segment 206 on the workpiece 116. The near net shape component204 may include an extension segment 206 that is substantially congruentwith the workpiece 116 (and/or the workpiece-interface perimeter 504),such that the extension segment 206 aligns with the workpiece 116(and/or the workpiece-interface perimeter 504) with sufficientcongruency that a near net shape component 204 may be provided withoutrequiring a subsequent subtractive modification apart from surfacefinishing such as polishing, buffing, and the like. The extensionsegments 206 may be additively printed on the respectiveworkpiece-interfaces 120 such that the extension segments 206 aresubstantially congruent with the workpieces 116 and/or the work-pieceinterfaces 120. For example, the workpiece-interface 120 may have aworkpiece-interface perimeter 504 (FIG. 5B), and the extension segments206 may be additively printed on the respective workpiece-interfaces 120such that the extension segment 206 is substantially congruent with theworkpiece-interface perimeter 504. The extension segments 206 mayinclude an interface layer that is substantially congruent with theworkpiece-interface 120, including an interface layer perimeter that issubstantially congruent with the workpiece-interface perimeter 504. Inan exemplary embodiment, an extension segment 206 additively printed ona workpiece-interface 120 may be regarded as substantially congruentwith the workpiece 116 (and/or the workpiece-interface perimeter 504)when the workpiece 116 is an airfoil (e.g., a compressor blade or aturbine blade) having a workpiece-interface 120 in the form of acrescent shape and the extension segment 206 also has a crescent shapedetermined at least in part based on a digital representation of theworkpiece-interface 120 of the workpiece 116.

In some embodiments, as shown in FIG. 5C, the component 204 may includean overhang 506, such that the extension segment 206 overhangs theworkpiece-interface 120 (e.g., the workpiece-interface perimeter 504).Notwithstanding the presence of the overhang 506, the component 204 maybe regarded as a near net shape component 204, and/or the extensionsegment 206 may be regarded as being substantially congruent with theworkpiece 116 (and/or the workpiece-interface perimeter 504), such aswhen the overhang 506 does not require a subsequent subtractivemodification apart from surface finishing such as polishing, buffing,and the like. The purpose of the overhang 506 may be, for example, toleave a small portion of material available for such surface finishing,including polishing, buffing, and the like. The size of the overhang 506may be selected based on the nature of the finishing processes. Aftersuch finishing processes, the overhang 506 may be substantially removed.

By way of example, in some embodiments, the overhang 506 may be fromabout 1 micron to 1,000 microns, such as from about 1 μm to 500 μm, suchas from about 1 μm to 100 μm, such as from about 1 μm to 50 μm, such asfrom about 1 μm to 25 μm, such as from about 10 μm to 50 μm, such asfrom about 25 μm to 50 μm, such as from about 50 μm to 100 μm, such asfrom about 50 μm to 250 μm, such as from about 250 μm to 500 μm, such asfrom about 500 μm to 1,000 μm, such as about 1,000 μm or less, such asabout 500 μm or less, such as about 250 μm or less, such as about 100 μmor less, such as about, such as about 50 μm or less, or such as about 25μm or less. In an exemplary embodiment, the respective ones of aplurality of extension segments 206 may overhang the correspondingworkpiece-interface 120 of respective ones of the plurality ofworkpieces 116 with the overhang 506 having a maximum overhang distanceof about 1,500 microns or less, such as about 1,000 μm or less, such asabout 500 μm or less, or such as about 100 μm or less or such as about50 μm or less or such as about 25 μm or less. In some embodiments, anextension segment 206 may be regarded as being substantially congruentwith the workpiece 116 and/or the workpiece-interface perimeter 504 whenthe extension segment 206 includes an overhang 506 having a maximumoverhang distance of about 1,500 microns or less, such as about 1,000 μmor less, such as about 500 μm or less, or such as about 100 μm or lessor such as about 50 μm or less or such as about 25 μm or less.

While a workpiece-interface 120 may be relatively small, the additivemanufacturing machine 104 may nevertheless additively print an extensionsegment 206 thereon so as to provide a near net shape component 204. Forexample, as shown in FIG. 5B, a workpiece 116 may have aworkpiece-interface 120 with a cross-sectional width, w, and a height,h_(w), such that a ratio of the height of the workpiece 116 to thecross-sectional width may be from about 1:1 to 1,000:1, such as fromabout 1:1 to 500:1, such as from about 1:1 to 250:1, such as from about1:1 to about 100:1, such as from about 1:1 to about 75:1, such as fromabout 1:1 to about 65:1, such as from about 1:1 to about 35:1, such asfrom about 2:1 to about 100:1, such as from about 5:1 to about 100:1,such as from about 25:1 to about 100:1, such as from about 50:1 to about100:1, such as from 75:1 to about 100:1, such as at least 5:1, such asat least 10:1, such as at least 25:1, such as at least 50:1, such as atleast 75:1 such as at least 100:1, such as at least 250:1, such as atleast 500:1, such as at least 750:1.

As shown in FIG. 5C, an extension segment 206 may have a height, h_(e),such that a ratio of the cross-sectional width, w, of the workpiece 116to the height, h_(e), of the extension segment 206 may be from about1:1,000 to about 1,000:1, such as about 1:1,000 to about 1:500, such asabout 1:500 to about 1:100, such as about 1:100 to about 1:1, such asabout 1:10 to about 1:1, such as about 1:10 to about 10:1, such as about1:1 to about 1:1,000, such as about 1:1 to about 1:10, such as about 1:1to 100:1, such as about 1:1 to about 500:1, or such as about 500:1 toabout 1,000:1.

A ratio of the height, h_(w), of the workpiece 116 to the height, h_(e),of an extension segment 206 to may be from about 2:1 to about 10,000:1,such as from about 10:1 to about 1,000:1, such as from about 100:1 toabout 10,000:1, such as from about 100:1 to about 500:1, such as fromabout 500:1 to about 1,000:1, such as from about 1,000:1 to about10,000:1, such as from about 500:1 to about 5,000:1, such as from about2,500:1 to about 7,500:1, such as at least 2:1, such as at least 100:1,such as at least 500:1, such as at least 1,000:1, such as at least5,000:1, or such as at least 7,000:1.

In some embodiments, a workpiece 116 may have a cross-sectional width offrom about 0.1 millimeters to about 10 centimeters, such as about 0.1 mmto about 5 cm, such as 0.2 mm to about 5 cm, such as about 0.5 mm toabout 5 cm, such as about 0.5 mm to about 1 cm, such as about 0.1 mm toabout 0.5 mm, such as about 0.1 mm to about 5 mm, such as about 0.5 mmto about 10 mm, such as about 0.5 mm to about 5 mm, such as about 0.5 mmto about 3 mm, such as about 1 mm to about 5 mm, such as about 3 mm toabout 10 mm, such as about 1 cm to about 10 cm, such as about 10 cm orless, such as about 5 cm or less, such as about 3 cm or less, such asabout 1 cm or less, such as about 5 mm or less, such as about 3 mm orless, such as about 1 mm or less, such as about 0.5 mm or less. In otherembodiments, a workpiece 116 may have a relatively largercross-sectional width, such as from about 1 cm to about 25 cm, such asfrom about 5 cm to about 15 cm, such as from about 5 cm to about 10 cm,such as at least about 1 cm, such as at least about 5 cm, such as atleast about 10 cm, such as at least about 15 cm, or such as at leastabout 20 cm.

In some embodiments, a workpiece 116 may have a height, h_(w), of fromabout 0.5 centimes to about 25 centimeters, such as about 0.5 cm toabout 5 cm, such as about 0.5 cm to about 3 cm, such as about 1 cm toabout 3 cm, such as about 1 cm to about 10 cm, such as about 10 cm toabout 15 cm, such as about 15 cm to about 25, such as at least about 0.5cm, such as at least 1 cm, such as at least 3 cm, such as at least 5 cm,such as at least 1 about 0 cm, such as at least about 20 cm, such asabout 25 cm or less, such as about 20 cm or less, such as about 15 cm orless, such as about 10 cm or less, such as about 5 cm or less, such asabout 3 cm or less, or such as about 1 cm or less. In other embodiments,a workpiece 116 may have a relatively larger cross-sectional width, suchas from about 1 cm to about 25 cm, such as from about 5 cm to about 15cm, such as from about 5 cm to about 10 cm, such as at least 1 cm, suchas at least 5 cm, such as at least 10 cm, such as at least 15 cm, orsuch as at least 20 cm.

In some embodiments, an extension segment 206 may have a height, h_(e),of from about 10 microns to about 20 centimeters, such as about 10 μm toabout 1,000 μm, such as about 20 μm to about 1,000 μm, such as about 50μm to about 500 μm, such as about 100 μm to about 500 μm, such as about100 μm to about 1,000 μm, such as about 100 μm to about 500 μm, such asabout 250 μm to about 750 μm, such as about 500 μm to about 1,000 μm,such as about 1 mm to about 1 cm, such as about 1 mm to about 5 mm, suchas about 1 cm to about 20 cm, such as about 1 cm to about 5 cm, such asabout 5 cm to about 10 cm, such as about 10 cm to about 20 cm, such asabout 20 cm or less, such as about 10 cm or less, such as about 5 cm orless, such as about 1 cm or less, such as about 5 mm or less, such asabout 3 mm or less, such as about 1 mm or less, such as about 500 μm orless, such as about 250 μm or less.

In exemplary embodiment, a workpiece 116 may have a height, h_(w), offrom about 1 cm to 5 cm, and a cross-sectional width, w, of from about0.1 mm to about 5 mm, and an extension segment 206 additively printedthereon may have a height, h_(e), of from about 10 μm to about 5 mm,such as from about 100 μm to about 1 mm, or such as from about 1 mm toabout 5 mm. An exemplary workpiece 116 may have a ratio of the height,h_(w), of the workpiece 116 to the height, h_(e), of an extensionsegment 206 of from about 2:1 to about 10,000:1, such as about 2:1 toabout 10:1, such as about 10:1 to about 50:1, such as about 50:1 toabout 100:1, such as about 100:1 to about 1,000:1, such as about 1,000:1to 5,000:1, such as about 10:1 to about 10,000:1, such as about 2:1 toabout 100:1, such as about 50:1 to about 5,000:1, such as about 100:1 toabout 1,000:1, such as about 1,000:1 to about 5,000:1, such as about1,000:1 to about 10,000:1, such as about 5,000:1 to 1 about 0,000:1,such as at least 2:1, such as at least 10:1, such as at least 50:1, suchas at least 100:1, such as at least 500:1, such as at least 1,000:1,such as at least 5,000:1.

An exemplary workpiece 116 may have a ratio of the cross-sectionalwidth, w, of the workpiece 116 to the height, h_(e), of the extensionsegment 206 of from about 1:50 to about 1,000:1, such as about 1:10 toabout 1:1, such as about 1:5 to about 1:1, such as about 1:1 to about5:1, such as about 5:1 to about 10:1, such as about 10:1 to about 50:1,such as about 50:1 to about 100:1, such as about 100:1 to about 500:1,such as about 500:1 to about 1,000:1, such as about 2:1 to about1,000:1, such as about 1:2 to about 1:1, such as about 1:1 to 1,000:1,such as about 2:1 to about 10:1, such as about 5:1 to about 500:1, suchas about 10:1 to about 100:1, such as about 100:1 to 500:1, such asabout 100:1 to 1,000:1, such as about 500:1 to 1,000:1, such as at least2:1, such as at least 10:1, such as at least 50:1, such as at least100:1, such as at least 500:1.

Referring again to FIGS. 1A and 1B, exemplary methods of obtaining adigital representation of a field of view 114 using a vision system 102will be discussed. When the vision system 102 is integrated with theadditive manufacturing machine 104, the vision system 102 may capturedigital images of the workpieces 116 with the workpieces 116 secured tothe build plate 118, and the build plate 118 secured to the buildplatform 138. The chuck system 140 may position and align the buildplate 118 within the build chamber 128 and on the build platform 138with a high level of precision and accuracy, which also thereby alignsand positions the workpieces 116 within the build chamber 128. Thedigital images may also be captured prior to the build plate 118 havingbeen placed in the build chamber 128 and secured to the build platform138; however, generally it will be preferable to take advantage of thepositioning and alignment provided by the chuck system 140. When thevision system 102 is not integrated with the additive manufacturingmachine 104, digital images may be captured before the build plate 118has been placed in the build chamber 128 and secured to the buildplatform 138, such as in the case of a vision system 102 that isprovided as a separate unit from the additive manufacturing machine 104.

The digital images of the workpieces 116 may be captured during or afterpowder 126 has been added to the build chamber 128. However, the digitalimages are typically captured before distributing powder 126 all the wayup to the build plane 122 and/or across the workpiece-interfaces 120. Insome embodiments, a layer of powder 126 surrounding the workpieces 116but not covering the workpiece-interfaces 120 may help the vision system102 to obtain better digital images of the workpiece-interfaces 120. Forexample, the powder 126 may provide an improved background (e.g., bettercontrast, less reflection, more uniformity, etc.) that allows the one ormore cameras 112 to better focus on the workpiece-interfaces 120.However, powder 126 covering a portion of a workpiece-interface 120 mayreduce the quality of the digital images and may affect the reliabilityof the control system 106 in determining the respectiveworkpiece-interfaces 120. In some embodiments, a layer of powder 126 maybe added to the build chamber 128 that comes to just below the buildplane 122 and/or just below the workpiece-interfaces 120 prior to thedigital images of the workpieces 116 being captured. The digital imagesmay be captured with such a layer of powder 126 in place. Any straypowder 126 may be brushed away from the workpiece-interfaces 120 priorto capturing the digital images.

Exemplary digital representations of one or more fields of view 114captured using the vision system 102 are schematically depicted in FIGS.6A and 6B. FIG. 6A depicts a digital representation of a field of view114 that includes one workpiece 116, and FIG. 6B depicts a digitalrepresentation of one or more fields of view 114 that includes aplurality of workpieces 116. The digital representation depicted in FIG.6B may be captured from a single field of view 114, or a plurality offields of view 114 maybe stitched together to provide a digitalrepresentation of one or more fields of view 114 that includes aplurality of workpieces 116.

As shown in FIGS. 6A and 6B, a field of view 114 may include an area ofinterest 600 corresponding to a workpiece-interface 120 and/or aworkpiece 116 (FIG. 6A) or a plurality of areas of interest 600respectively corresponding to a plurality of workpiece-interfaces 120and/or workpieces 116 (FIG. 6B). Regardless of whether the field of view114 includes one or more areas of interest 600, an area of interest 600may correspond to an expected location of a workpiece-interface 120and/or a workpiece 116 within the field of view 114. The expectedlocation may be determined, for example, based on registration points202 (FIGS. 2A and 2B) mapped to a coordinate system. The control system106 may be configured to process only one or more areas of interest 600within a field of view 114 so as to reduce processing time. As shown,the area of interest 600 includes a digital representation of aworkpiece 116 situated therein. The field of view 114 shown may reflecta top view of the workpiece 116, such that the digital representation ofthe workpiece 116 includes a digital representation of aworkpiece-interface 120, which may include a digital representation ofthe workpiece-interface perimeter 504.

Now referring to FIG. 7A, exemplary methods of determining a workpiece116, a workpiece-interface 120, and/or a workpiece-interface perimeter504 of a workpiece 116 will be discussed. An exemplary method 700includes, at step 702, determining an area of interest 600 within thefield of view 114. The area of interest 600 may correspond to anexpected location of the workpiece 116, the workpiece-interface 120,and/or the workpiece-interface perimeter 504 within the field of view114. An area of interest may be identified based at least in part on amapping of coordinates of the field of view 114 to a registration point202 for a workpiece 116.

An exemplary method 700 may further include, at step 704, determining aworkpiece-interface perimeter 504 within the area of interest 600. Theworkpiece-interface perimeter 504 may be determined using an edgedetection algorithm. An exemplary edge detection algorithm may identifythe workpiece-interface perimeter 504 by identifying pixels within thedigital representation of the field of view 114 that havediscontinuities, such as changes in brightness or contrast. Theworkpiece-interface 120 and/or the workpiece 116 may be determined basedon the workpiece-interface perimeter 504 determined using the edgedetection algorithm. Any suitable edge detection algorithm may beutilized, including first or second order operations. Exemplary edgedetection algorithms include a Canny algorithm, a Sobel algorithm, aPrewitt algorithm, a Roberts algorithm, a thresholding algorithm, adifferential algorithm, a fuzzy logic algorithm, and so forth. Thedigital images may also be filtered using edge thinning, a Gaussianfilter, or the like. Exemplary edge detection algorithms may determine aworkpiece-interface perimeter 504 with sub-pixel accuracy.

Good contrast between the workpiece-interface 120 and the surroundingportions of the area of interest 600 (and/or between theworkpiece-interface perimeter 504 and the surrounding portions of thearea of interest 600) may improve the performance of the edge detectionalgorithm. In some embodiments, image capture may be improved byintroducing a layer of powder 126 to the build chamber 128 that comes tojust below the build plane 122 and/or just below theworkpiece-interfaces 120, which is sometimes referred to as a “scratchcoating.” Additionally, or in the alternative, in some embodiments, askirt (not shown) may be utilized that include slits for theworkpiece-interfaces 120 to slip through. The skirt may be placed overthe workpieces 116 when secured to the build plate 118, leaving theworkpiece-interfaces 120 exposed for purposes of obtaining digitalimages, and then the skirt may be removed prior to additive printing.

An exemplary method 700 may include, at step 706, generating a pointcloud 602 corresponding to a workpiece-interface perimeter 504, aworkpiece-interface 120, and/or a workpiece 116. The point cloud mayinclude any desired number of points corresponding to theworkpiece-interface perimeter 504, the workpiece-interface 120, and/orthe workpiece 116. The number of points may be selected based on thedesired level of resolution of the point cloud 602. An exemplary pointcloud 602 is shown in FIGS. 6A and 6B. In some embodiments, as shown inFIG. 6A, a point cloud 602 may be offset by an offset amount 604corresponding to an intended overhang distance between theworkpiece-interface perimeter 504 and an extension segment 206 to beadditively printed thereon. When providing such an offset in the pointcloud 602, the step 706 of generating the point cloud 602 may includedetermining an offset amount 604 and offsetting the series of points ofthe point cloud 602 by the offset amount 604. In some embodiments, theoffset amount may vary as between a first point along the perimeter 504and a second point along the perimeter 504. For example, the offsetamount may be configured to vary according to curvature and/or toolpathof the additive manufacturing tool.

As discussed with reference to FIG. 4, in an exemplary method 400 ofadditively printing an extension segment 206, after determining aworkpiece-interface 120 from the digital representation of the field ofview 114, the exemplary method 400 may include, at step 406,transmitting to an additive manufacturing machine 104, a print commandconfigured to additively print the extension segment 206 on theworkpiece-interface 120, and optionally, the exemplary method 400 mayinclude, at step 408, generating the print command based at least inpart on the field of view 114.

In some embodiments, the print command may be based at least in part ona CAD model, such as an extension segment-CAD model that includes amodel of one or more extension segments 206 configured to be additivelyprinted on one or more workpieces 116, such as on the respectiveworkpiece-interfaces 120. The exemplary method 400 may includedetermining an extension segment-CAD model and/or generating anextension segment-CAD model. Additionally, or in the alternative, thestep 408 of generating a print command based at least in part on thefield of view 114 captured by the vision system 102 may includedetermining an extension segment-CAD model and/or generating anextension segment-CAD model.

FIG. 7B shows an exemplary method 750 of generating a print command,such as at step 408 in the exemplary method of additively printing anextension segment 206 shown in FIG. 4. An exemplary method 750 includesdetermining and/or generating an extension segment-CAD model 752,slicing the extension segment-CAD model 754, and determining a toolpathand an additive printing area for each slice of the extensionsegment-CAD model 756. After determining a toolpath and an additiveprinting area for a slice of the extension segment-CAD model 756, theexemplary method 750 determines whether there is another slice 758, andif so, the exemplary method 750 may proceed to step 756, providing fordetermining a toolpath and an additive printing area for a next slice ofthe extension segment-CAD model 800. The exemplary method 750 may endwhen there are no additional slices for which a toolpath and additiveprinting area may be determined. The number of slices may depend on thesize (e.g., height, thickness) of the extension segment(s) in theextension segment-CAD model, as well as the desired thickness of thelayers of powder 126 or other material that may be used to additivelyprint the extension segment(s).

FIG. 8A shows an exemplary extension segment-CAD model 800. Theexemplary extension segment-CAD model 800 may include a model of one ormore extension segments 206. As shown, the extension segment-CAD model800 includes a plurality of models of extension segments 802. The modelsof the extension segments 802 respectively conform to the location andshape of a plurality of corresponding workpieces 116 upon which theplurality of extension segments 206 are to be respectively additivelyprinted. For example, the respective models of an extension segment 802may be aligned with coordinates that respectively correspond to theregistration points 202 of a plurality of workpieces 116 secured to abuild plate 118, and/or the models of the extension segments 802 mayinclude a model-interface 804 that is substantially congruent with theworkpiece-interface 120 of the corresponding workpiece 116. Themodel-interface 804 may be defined by a model-interface perimeter 806,and the model-interface perimeter 806 may be substantially congruentwith the workpiece-interface perimeter 504 of the respective workpiece116. A model of the extension segment 802 may include a height, h_(e),extending from a model-interface 804 to a top surface 808.

In some embodiments, a plurality of workpieces 116 onto which extensionsegments 206 are to be printed may differ from one another, and yet theextension segment-CAD model 800 may nevertheless include a model of theplurality of extension segments 802 conforming to the location and shapeof respective ones of the plurality of workpieces 116. The model mayinclude one or more model-interfaces 804 that are substantiallycongruent with corresponding workpiece-interfaces 120 and/or one or moremodel-interface perimeter 806 that are substantially congruent withcorresponding workpiece-interface perimeters 504. An extensionsegment-CAD model 800 may be determined and/or generated based at leastin part on a CAD model, such as a library-CAD model selected from adatabase or CAD model library. The database or CAD model library mayinclude a plurality of library-CAD models from which an extensionsegment-CAD model 800 may be determined and/or generated.

An exemplary library-CAD model is shown in FIG. 8B. A library-CAD model850 may include a nominal model of one or more nominal workpieces 116,components 204, or extension segments 206. For example, as shown in FIG.8B, the library-CAD model 850 may include a nominal model 852 of one ormore components 204 intended to be repaired, rebuilt, and/or upgraded.As shown, the library-CAD model 850 may include a nominal model 852 of aplurality of nominal components 204. The library-CAD model 850 mayalternatively include a single nominal component 204. Additionally, orin the alternative, the library-CAD model 850 may include one or morenominal models 852 of a nominal extension segment 206, and/or one ormore nominal models 852 of a nominal workpiece 116. In some embodiments,the CAD model library may include one or more extension segment-CADmodels 800, which may include one or more previously determined and/orpreviously generated extension segment-CAD models 800 from whichsubsequent extension segment-CAD models 800 may be determined and/orgenerated.

As shown in FIG. 8B, a nominal model-interface 854 may be determinedfrom a nominal model 852. A nominal model-interface 854 may correspondto an expected location of a workpiece-interface 120 of a nominalworkpiece 116 associated with the library-CAD model 850. The nominalmodel-interface 854 may be defined by a nominal model-interfaceperimeter 856, and the nominal model-interface perimeter 856 may or maynot be substantially congruent with the workpiece-interface perimeter504 of the respective workpiece 116. The nominal model-interface 854 maybe located at any z-directional position of the nominal model, includingup to a nominal top surface 858 of the nominal model 852.

In some embodiments, a library-CAD model 850 or an extension segment-CADmodel 800 may be an actual CAD model from which one or more components204 were originally fabricated, or the library-CAD model may be a copyor a modified version of a CAD model from which one or more components204 were originally fabricated. While a library-CAD model 850 maygenerally correspond to one or more workpieces 116 onto which anextension segment 206 is to be additively printed, the one or moreworkpieces 116 may differ from their original net shape in varyingdegrees from one workpiece 116 to the next. A difference from suchoriginal net shape may exits, for example, when a workpiece 116 has beendeformed or damaged such as from exposure to extreme temperatureoperating conditions and/or from rubbing or impacts from foreignobjects. A difference in original net shape may also exist because ofvariations in a subtractive modification performed to prepare aworkpiece-interface 120 on the workpieces 116. However, the presentdisclosure provides for generating extension-segment CAD models 800 thatinclude a plurality of models of extension segments 802 respectivelyconforming to the location and shape of a plurality of workpieces 116upon which the plurality of extension segments 206 are to berespectively additively printed based on an extension-segment CAD model800 and/or the models of the extension segments 802 therein.

An exemplary method of generating an extension segment-CAD model 800 isshown in FIGS. 9A and 9B. As shown in FIG. 9A, an exemplary method 900of generating an extension segment-CAD model 800 may be performed foreach of a plurality of workpieces 116. An exemplary method 900 mayinclude, at step 902, determining in a library-CAD model, a nominalmodel-interface 854 traversing a nominal model corresponding to arespective one of the plurality of workpieces 116. The nominal model mayinclude a model of a nominal component 204, such as a model of acomponent 204 from which the workpieces 116 may have originated. Theworkpieces 116 may, however, differ from a component 204 having beenadditively manufactured according to the nominal model, for example,because of damage or wear incurred by the workpieces 116 as a result ofthe environment with which the component 204 was used, and/or from asubtractive modification performed to prepare the workpiece 116 for anextension segment 206 to be additively printed thereon. The nominalmodel may additionally or alternatively include a model of a nominalworkpiece, such as a nominal model of a workpiece 116 produced bysubjecting a nominal component 204 to a subtractive modification processto provide a workpiece-interface 120. The nominal model may additionallyor alternatively include a model of a nominal extension segment 802,such as a nominal model of an extension segment 802 corresponding to anominal workpiece 116.

Determining a nominal model-interface 854 may include determining aplane traversing the library-CAD model at a determined height. Thedetermined height may correspond to a height of an expected location ofa workpiece-interface 120 for a nominal workpiece 116. By way ofexample, a library-CAD model may include a model of a nominal component204 corresponding to the workpiece, and the workpiece 116 may have beensubjected to a subtractive modification, such as to provide aworkpiece-interface 120. An expected location of a workpiece-interface120 may be determined based at least in part on the nature of thesubtractive modification, such as based on an expected amount ofmaterial removed or a resulting change in height of the workpiece 116 asa result of the subtractive modification.

Additionally, or in the alternative, the determined height maycorrespond to a height of a workpiece-interface 120 as determined from adigital representation of the workpiece 116. The height of aworkpiece-interface 120 may be measured based at least in part on one ormore dimensions of the workpiece 116 obtained from the digitalrepresentation of the workpiece, and a nominal model-interface 854 maybe determined based at least in part on the measured height.Additionally, or in the alternative, the height of theworkpiece-interface 120 may be measured based at least in part one ormore dimensions of a workpiece alignment system 200 captured in a fieldof view 114. For example, a height of the workpiece-interface 120 may bedetermined based at least in part on the height of a workpiece shoe 214,or based at least in part on a difference between the height of theworkpiece-interface 120 and the height of a workpiece shoe 214, or basedat least in part on a difference between the height of theworkpiece-interface 120 and the height of the build plate 118.

In some embodiments, a nominal model-interface 854 may be determinedusing a best-fit algorithm. Determining the nominal model-interface 854traversing the library-CAD model 850 may include determining a planetraversing the library-CAD model that meets a metric associated with abest-fit algorithm applied with respect to the digital representation ofthe workpiece-interface 120. The best-fit algorithm may compare one ormore planes traversing the library-CAD model to the digitalrepresentation of the workpiece-interface 120 until a compared planesatisfies the best-fit metric. The nominal model-interface 854 may bedetermined based at least in part on a plane that satisfies the best-fitmetric. For example, a plane that satisfies the best-fit metric may bedetermined to be the nominal model-interface 854.

Still referring to FIG. 9A, an exemplary method 900 of determiningand/or generating an extension segment-CAD model 800 may include, atstep 904, comparing the nominal model-interface 854 of the library-CADmodel to a digital representation of the workpiece-interface 120 of therespective ones of the plurality of workpieces 116. The digitalrepresentation may have been previously or concurrently obtained using avision system 102 that has a field of view 114 including theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116. The comparison may be performed using imaging matchingalgorithm. In some embodiments, comparing the nominal model-interface854 to the digital representation of the workpiece-interface 120 mayinclude, at step 906, determining whether the nominal model-interface854 and the digital representation of the workpiece-interface 120sufficiently match one another. However, in some embodiments a matchingstep 906 need not be included.

When include, a matching step 906 may include comparing one or morecoordinates of the nominal model-interface 854 with one or morecoordinates of the digital representation of the workpiece-interface 120and determining one or more differences therebetween. The comparing step904 may additionally or alternatively include comparing one or morecoordinates of the one or more registration points 202 with acorresponding one or more coordinates of the nominal model-interface 854of the library-CAD model and determining one or more differencestherebetween. The registration points 202 may correspond to locations ofrespective ones of a plurality of workpieces 116 onto which respectiveones of a plurality of extension segments 206 are to be additivelyprinted using the additive manufacturing machine 104. The comparing step904 and the matching step 906 may be performed separately or together aspart of the same step. In some embodiments, the matching step 906 maydetermine whether there is a partial match, a close match, or no matchbetween the nominal model-interface 854 and the workpiece-interface 120.Alternatively, the matching step 906 may determine whether there is anymatch (e.g., at least a partial match), or no match between the nominalmodel-interface 854 and the workpiece-interface 120.

When the matching step 906 determines that there is at least a partialmatch between the nominal model-interface 854 and theworkpiece-interface 120, the exemplary method 900 may proceed to step908, providing for generating a model of an extension segment 802 basedat least in part on the nominal model-interface 854. Step 908 provides amodel of an extension segment 802 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116 such that the model of the extensionsegment 802 is configured to be additively printed on theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116.

When the matching step 906 determines that there is not at least apartial match between the nominal model-interface 854 and theworkpiece-interface 120, the exemplary method 900 may return to step 902so as to determine a different nominal model-interface 854 and tocompare the different nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120. The different nominalmodel-interface 854 may be selected form the same library-CAD model or adifferent library-CAD model.

In some embodiments, the matching step 906 may include determiningwhether there is more than a partial match, such as a close matchbetween the nominal model-interface 854 and the workpiece-interface 120.When the matching step 906 determines that there is a close matchbetween the nominal model-interface 854 and the workpiece-interface 120,the exemplary method 900 may include, at step 910, selecting the nominalmodel-interface 854 and/or at least a three-dimensional portion of thenominal model from the library-CAD model based at least in part on thecomparison. For example, the comparison may determine that the selectednominal model-interface 854 and/or the nominal model from thelibrary-CAD model conforms to the digital representation of theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116, such that the selected nominal model-interface 854 maybe aligned with coordinates that correspond to the digitalrepresentation of the workpiece-interface 120, and/or the selectednominal model-interface 854 may be substantially congruent with thedigital representation of the workpiece-interface 120. In variousexemplary embodiments, step 910 may include selecting the entire nominalmodel for a respective workpiece, selecting a three-dimensional portionof the nominal model for a respective workpiece 116 (which may includethe nominal model-interface 854), and/or selecting only the nominalmodel-interface 854 for the respective workpiece 116.

When a nominal model or a three-dimensional portion thereof is selectedat step 908, the exemplary method 900 may include determining anextension-segment-CAD model from the library-CAD model. For example, alibrary-CAD model that includes a nominal extension segment 206 may bedetermined to sufficiently match a workpiece-interface 120 such that anextension segment 206 may be additively printed on theworkpiece-interface 120 without requiring transforming or extending thenominal model-interface 854 at steps 910, 912. On the other hand, whenthe library-CAD model includes a model of a nominal component 204 or amodel of a nominal workpiece 116, rather than a model of a nominalextension segment 206, the exemplary method 900 may proceed withgenerating a model of an extension segment 802 at step 908, for example,so as to provide a model of an extension segment 802 rather than a modelof a component 204 or workpiece 116. The model of the extension segment802 generated at step 908 may be configured to be additively printed onthe workpiece-interface 120 of the respective one of the plurality ofworkpieces 116, whereas a model of a component 204 or workpiece 116would not be so configured even if the nominal model-interface 854closely matched the workpiece-interface 120.

In exemplary methods 900 that do not include a matching step 906, anexemplary method may proceed to generating a model of an extensionsegment 802 based at least in part on the nominal model-interface 854 atstep 908 after having compared the nominal model-interface 854 to thedigital representation of the workpiece-interface 120 at step 904. Insome embodiments, steps 904 and 908 may be combined into a single step,such that comparing the nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120 may be part of the processof generating a model of an extension segment 802 based at least in parton the nominal model-interface 854.

After having generated and/or selected a model of an extension segment802 at steps 908, 910, an exemplary method 900 may ascertain, at step912, whether the plurality of workpieces 116 includes another workpiece116. When there is another workpiece, the exemplary method 900 mayinclude repeating the determining step 902 and subsequent steps throughto step 912. When step 912 indicates that there are no additionalworkpieces 116, the exemplary method 900 may proceed with step 914,which provides for outputting a model of a plurality of extensionsegments 802 respectively configured to be additively printed on thecorresponding workpiece-interface 120 of the respective ones of theplurality of workpieces 116. The model may be an extension segment-CADmodel 800, and the model may be based at least in part on the selectingand/or transforming of the nominal model-interface 854 and/or thenominal model from the library-CAD model.

The model of the plurality of extension segments 802 may be output atstep 914 concurrently as, or subsequently after, each additionalworkpiece 116 is generated and/or selected at steps 908, 910. In someembodiments, outputting the model may include stitching together aplurality of models, such as models having been respectively selectedand/or transformed and generated for respective ones of the plurality ofworkpieces 116. While an exemplary method 900 of determining and/orgenerating an extension segment-CAD model 800 has been described withrespect to a plurality of extension segments 206, it will be appreciatedthat an extension segment-CAD model 800 may also be determined and/orgenerated for a single extension segment 206. For example, the exemplarymethod 900 may be performed for a single extension segment 206.

Referring now to FIG. 9B, one or more steps will be described that maybe included in the step 908 of generating a model of an extensionsegment 802 (FIG. 9A). The steps shown in FIG. 9B may be includedindividually or together with one or more other steps. When generating amodel of an extension segment 802, one or more steps shown in FIG. 9Bmay be performed, and the particular steps performed may depend at leastin part on whether the nominal model-interface 854 provides a partialmatch or a close match at step 906 (FIG. 9A), and/or whether the nominalmodel-interface 854 or at least a three-dimensional portion of thenominal model are selected at step 910 (FIG. 9A).

As shown in FIG. 9B, generating a model of an extension segment 802 atstep 908 may include an extracting step 916, such that an extensionsegment 206 may be generated based at least in part on a nominalmodel-interface 854 and/or a three-dimensional portion of a nominalmodel corresponding to the nominal model-interface 854. Alternatively,the extracting step 916 may be omitted, for example, such that a nominalmodel may itself be configured to be additively printed on aworkpiece-interface 120. The step 908 of generating a model of anextension segment 802 may additionally or alternatively include atransforming step 918, such that a nominal model-interface 854 may beconformed to the digital representation of the workpiece-interface 120.Alternatively, the transforming step 918 may be omitted, for example,when a nominal model-interface 854 already conforms to the digitalrepresentation of the workpiece-interface 120. The step 908 ofgenerating a model of an extension segment 802 may further additionallyor alternatively include an extending step 920, such that a nominalmodel-interface 854 or a transformed model-interface 804 may be extendedso as to provide a three-dimensional model of an extension segment 802.Alternatively, the extending step 920 may be omitted, for example, whengenerating a model of an extension segment 802 from a three-dimensionalportion of the nominal model.

In some embodiments, at step 916, generating a model of an extensionsegment 802 may optionally include extracting from a nominal model basedat least in part on the comparison at step 904, 906, a nominalmodel-interface 854 and/or a three-dimensional portion of the nominalmodel corresponding to the nominal model-interface 854. The extractingstep may be performed following the comparing step 904, following thematching step 906, or following the selecting step 910.

In some embodiments, generating a model of an extension segment 802 mayoptionally include, at step 918, transforming a nominal model-interface854 based at least in part on the comparison at step 904, 906, so as toprovide a transformed model-interface 804 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116. The transforming step may include onemore transforming operations, including aligning, altering, modifying,contorting, distorting, deforming, correcting, adjusting, revising,straightening, tilting, rotating, bending, twisting, or editing, as wellas combinations of these. The particular transforming operation(s) maybe selected based at least in part on the comparison such that thetransforming operation(s) conforms the nominal model-interface 854 tothe digital representation of the workpiece-interface 120.

The transforming step 918 may be performed following the comparing step904 and/or following the matching step 906. Additionally, or in thealternative, the transforming step 918 may be performed following theextracting step 916. An exemplary method 900 may include extracting thenominal model-interface 854 from the nominal model and then proceedingto step 918, providing for transforming the nominal model-interface 854based at least in part on the comparison at step 904, 906, so as toprovide a transformed model-interface 804 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116.

In some embodiments, generating a model of an extension segment 802 mayoptionally include, at step 920, extending the transformedmodel-interface 804, such that the extension segment 206 is configuredto be additively printed on the workpiece-interface 120 of therespective one of the plurality of workpieces 116. Step 920 may beperformed after having transformed the nominal model-interface 854 atstep 918. Alternatively, in some embodiments, the extending step 920 maybe combined with the transforming step 918.

Further additionally, or in the alternative, step 918 may follow step910 (FIG. 9A), providing for extending a nominal model-interface 854that has been selected at step 910. For example, when a nominalmodel-interface 854 closely matches a digital representation of aworkpiece-interface 120, such as may be determined at step 906, thetransforming step 918 may be omitted from the step of generating a modelof an extension segment 802 at step 908. Regardless of whether thenominal model-interface 854 is transformed at step 918 or selected atstep 910 with the transforming step 918 being omitted, the extensionsegment 206 resulting from the extending step 912 may be configured tobe additively printed on the workpiece-interface 120 of the respectiveone of the plurality of workpieces 116.

In an exemplary embodiment, generating a model of an extension segment802 at step 908 may include, at step 916, extracting from the nominalmodel based at least in part on the comparison of the nominalmodel-interface 854 to a digital representation of workpiece-interface120; at step 918, transforming the nominal model-interface 854 based atleast in part on the comparison so as to provide a transformedmodel-interface 804 conforming to the digital representation of theworkpiece-interface 120; and at step 920, extending the transformedmodel-interface 804 so as to provide an extension segment 206 configuredto be additively printed on the workpiece-interface 120.

Referring still to FIG. 9B, in another embodiment, the step 908 ofgenerating a model of an extension segment 206 may include, at step 916,extracting from the nominal model a three-dimensional portion of thenominal model. The three-dimensional portion may correspond to thenominal model-interface 854. For example, the three-dimensional portionmay include the portion of the nominal model above the nominalmodel-interface 854 and may include the nominal model-interface 854. Theportion of the nominal model below the three-dimensional interface maybe deleted from the nominal model and/or may remain unextracted. Thethree-dimensional portion may have a height corresponding to the heightof an extension segment 206 being generated at step 908.

In some embodiments, generating a model of an extension segment 802 mayoptionally include, at step 922, transforming a three-dimensionalportion of a nominal model corresponding to a nominal model-interface854 based at least in part on the comparison at step 904, 906, so as toprovide a model of an extension segment 802 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116. The model of the extension segment 802so provided may be configured to be additively printed on theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116. The three-dimensional portion of the nominal modeltransformed at step 922 may include a three-dimensional portionextracted at step 916 or at least a three-dimensional portion of anominal model selected at step 910 (FIG. 9A). In some embodiments, theat least a three-dimensional portion of a nominal model selected at step910 may include the entire nominal model, such as when the nominal modelis a model of a nominal extension segment 206.

The step 922 of transforming a three-dimensional portion may includetransforming the nominal model-interface 854 of the three-dimensionalportion, and may include one more transforming operations, includingaligning, altering, modifying, contorting, distorting, deforming,correcting, adjusting, revising, straightening, tilting, rotating,bending, twisting, or editing, as well as combinations of these. Theparticular transforming operation(s) at step 922 may be selected basedat least in part on the comparison such that the transformingoperation(s) conforms the nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120. Additionally, or in thealternative, the step 922 of transforming a three-dimensional portionmay include extending the nominal model-interface 854 so as to providean extension segment 206 conforming to the digital representation of theworkpiece-interface of the respective one of the plurality of workpieces116.

Now referring to FIGS. 10A-10D, exemplary transforming operations 1000will be described, which may be performed at step 910 in the exemplarymethod 900 of generating an extension segment-CAD model 800. Any one ormore transforming operations 1000 may be performed so as to conform anominal model-interface 854 to a digital representation of aworkpiece-interface 120. Such transforming operations 1000 may beperformed when transforming the nominal model-interface 854, forexample, as part of a transforming step 910 in an exemplary method 400of additively printing an extension segment 206 and/or in an exemplarymethod 900 of determining and/or generating an extension segment-CADmodel 800.

The nominal model-interface 854 may differ from a digital representationof a workpiece-interface 120, for example, because of a change to theshape of a workpiece 116 while in service, or any other differencebetween workpiece-interface 120 and the library-CAD model from which thenominal model-interface 854 was selected. Additionally, or in thealternative, a nominal model-interface 854 may be selected at a heightthat differs from the height of the workpiece-interface 120 even thoughthe nominal model corresponds to the component 204. Such a difference inheight may result in a corresponding difference between the nominalmodel-interface 854 and the workpiece-interface 120. The transformingoperation 1000 may be performed so as to compensate for a differencebetween the nominal model-interface 854 and the workpiece-interface 120,regardless of the underlying source for such difference.

FIG. 10A shows an exemplary transforming operation 1000 that includesshifting at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 with a digital representation ofa workpiece-interface 120. As shown in FIG. 10A, the nominalmodel-interface 854 is shifted to the right. However, it will beappreciated that a transforming operation 1000 may include shifting anominal model-interface 854 in any direction, including any directionalong a 360-degree axis.

FIG. 10B shows an exemplary transforming operation 1000 that includesrotating at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 with a digital representation ofa workpiece-interface 120. As shown in FIG. 10B, the nominalmodel-interface 854 is rotated counterclockwise. However, it will beappreciated that a transforming operation 1000 may include rotating anominal model-interface 854 in any direction.

FIG. 10C shows an exemplary transforming operation 1000 that includesbending at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 to a digital representation of aworkpiece-interface 120. As shown in FIG. 10C, by way of example nominalmodel-interface 854 generally aligns with the workpiece-interface 120 ata middle region, while outward regions are subjected to a bendingtransforming operation. However, it will be appreciated that atransforming operation 1000 may include bending a portion of a nominalmodel-interface 854 in any direction.

FIG. 10D shows an exemplary transforming operation 1000 that includesscaling at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 with a digital representation ofa workpiece-interface 120. As shown in FIG. 10D, by way of example, thenominal model-interface 854 is scaled downward so as to conform to theworkpiece-interface 120. However, it will be appreciated that atransforming operation 1000 may additionally or alternatively includescaling a nominal model-interface 854 upward.

Any one or more transforming operations may be carried out alone or incombination with one another, and as to all or a portion of a nominalmodel-interface 854. In some embodiments, transforming a nominalmodel-interface 854, such as at step 910 of the exemplary method 900,may include aligning at least a portion of the nominal model-interface854 with a digital representation of a workpiece-interface 120. Suchaligning may include aligning one or more coordinates of the nominalmodel-interface 854 with one or more coordinates of the digitalrepresentation of the workpiece-interface 120. By way of example, suchaligning may be performed, at least in part, using a shifting, rotating,bending, and/or scaling transforming operation as described withreference to FIGS. 10A-10D. Additionally, or in the alternative,transforming the nominal model-interface 854 may include a firsttransforming operation selected to align at least a first portion of thenominal model-interface 854 with a digital representation of aworkpiece-interface 120, such as using a shifting and/or rotatingtransforming operation as described with reference to FIGS. 10A and 10B,followed by a second transforming operation selected to align at least asecond portion of the nominal model-interface 854 with the digitalrepresentation of the workpiece-interface 120 such as using a bendingand/or scaling transforming operation as described with reference toFIGS. 10C and 10D.

The first transforming operation may be selected to align a first one ormore coordinates of the nominal model-interface 854 with a first one ormore coordinates of the digital representation of theworkpiece-interface 120, and the second transforming operation may beselected to align a second one or more coordinates of the nominalmodel-interface 854 with a second one or more coordinates of the digitalrepresentation of the workpiece-interface 120.

The first one or more coordinates of the nominal model-interface 854 mayinclude coordinates for a center point of the nominal model-interface854 and/or one or more coordinates along the nominal model-interfaceperimeter 856 of the nominal model-interface 854, such as a maximum orminimum X coordinate or a maximum or minimum Y coordinate along thenominal model-interface perimeter 856. The first one or more coordinatesof the workpiece-interface 120 may include coordinates for a centerpoint of the workpiece-interface 120 and/or one or more coordinatesalong the workpiece-interface perimeter 504 of the workpiece-interface120, such as a maximum or minimum X coordinate or a maximum or minimum Ycoordinate of the workpiece-interface perimeter 504. The firsttransforming operation may be configured to align the center point ofthe nominal model-interface 854 with the center point of theworkpiece-interface 120, and/or to align a maximum or minimum Xcoordinate or a maximum or minimum Y coordinate along the nominalmodel-interface perimeter 856 with a corresponding maximum or minimum Xor Y coordinate along the workpiece-interface perimeter 504.

The second one or more coordinates of the nominal model-interface 854may include one or more coordinates along the nominal model-interfaceperimeter 856 of the nominal model-interface 854, and the second one ormore coordinates of the workpiece-interface 120 may include one or morecoordinates along the workpiece-interface perimeter 504. The second oneor more coordinates of the nominal model-interface 854 and/or the secondone or more coordinates of the workpiece-interface 120 may be selectedbased on a comparison of the workpiece-interface 120. Such comparisonmay be performed, for example, after the first transforming operation.

Coordinates may be selected for the second transforming operation basedon a difference between coordinates for a point along the nominalmodel-interface perimeter 856 as compared to coordinates of acorresponding point along the workpiece-interface perimeter 504. Forexample, coordinates for such a point may be selected when thecoordinates differ by a threshold amount. The threshold amount may beselected based at least in part on a degree of conformance sufficient toprovide a near net shape component 204 when additively printing anextension segment 206 conformed to the workpiece-interface 120 based atleast in part on the one or more transforming operations. In this way,once the nominal model-interface 854 has been aligned with theworkpiece-interface 120 according to the first transforming operation,one or more second transforming operations may be performed asdetermined by such comparison relative to such threshold amount.

The one or more second transforming operations may be performed to theextent needed to sufficiently conform the nominal model-interface 854 tothe workpiece-interface 120 so as to obtain a near net shape component204. In some embodiments, a difference may exist between coordinates ofone or more points along the nominal model-interface perimeter 856relative to coordinates of corresponding points along theworkpiece-interface perimeter 504, while still sufficiently conformingthe nominal model-interface 854 to the workpiece-interface 120 so as toprovide a near net shape component 204. For example, such difference maybe an amount that is at least less than an overhang distance for anoverhang 506.

In some embodiments, a transforming operation may provide for anoverhang 506 between the workpiece-interface 120 and the model-interface804, such that the model-interface 804 overhangs the workpiece-interface120 by an overhang distance. For example, a transforming operation mayinclude determining an offset amount 604 and transforming at least aportion of a nominal model-interface 854 by the offset amount 604. Theoffset amount 604 may correspond to an overhang distance for at least aportion of the extension segment 206.

Now referring to FIGS. 11A and 11B, and FIGS. 12A-12D, exemplary methodsof extending a model-interface 804 will be described. FIG. 11A shows anominal model, such as from a library-CAD model 852. FIG. 11B shows amodel of an extension segment 802, such as in an extension segment-CADmodel 800, generated based at least in part on the nominalmodel-interface 854, such as in steps including extending the nominalmodel-interface 854. FIG. 12 shows a flow chart depicting exemplarymethods of extending a model-interface 804 so as to provide a model ofthe extension segment 802 configured to be additively printed on aworkpiece-interface 120 of a respective workpiece 116.

Exemplary methods of extending a model-interface 804 may be performedstarting from a nominal or transformed model-interface 804 and/or athree-dimensional portion of a nominal model. As described withreference to FIGS. 9A and 9B, exemplary methods 900 of generating anextension segment-CAD model 800 may include, at step 920, extending aselected nominal model-interface 854 or a transformed model-interface804. Additionally, the step 922 of transforming a three-dimensionalportion may include extending the nominal model-interface 854. Such anominal model-interface 854 may have been extracted from the nominalmodel or may remain part of the nominal model when extending the nominalmodel-interface 854. When a nominal model-interface 854 and/or athree-dimensional portion of a nominal model remains part of the nominalmodel when extending, the resulting extension segment 206 may beextracted from the nominal model, for example, by extracting athree-dimensional portion of a nominal model corresponding to thenominal model-interface 854 as described with reference to step 916.

As shown in FIG. 11B, a model of an extension segment 802 may include aheight, h_(e), extending from a model-interface 804 to a top surface808. The height, h_(e), for an extension segment 802 may be determinedfrom a nominal model 852. For example, the height of an extensionsegment 206, h_(e), may correspond to the z-directional distance from anominal model-interface 854 to a nominal top surface 858 of the nominalmodel 852. Alternatively, the height of an extension segment 206, h_(e),may be specified independently from the nominal model 852. An exemplarymodel of an extension segment 802 may be extended from themodel-interface 804 to the nominal top surface 858 of the nominal model852.

In some embodiments, a model of an extension segment 802 may include aregion extending from the model-interface 804 to the top surface 808 ofthe model. Additionally, or in the alternative, as shown in FIG. 11B, amodel of an extension segment 802 may include a plurality of extensionsegment slices 1100 between the model-interface 804 to the top surface808 of the model. The extension segment slices 1100 may correspond tonominal model slices 1102 in the nominal model 852. The nominal modelslices 1102 and/or the extension segment slices 1100 may have anydesired z-directional spacing. The nominal model slices 1102 may includea nominal model-interface 854 and/or one or more nominal extended-planes1104. The nominal model slices 1102 may correspond to the z-directionalresolution of the nominal model, and the extension segment slices 1100may correspond to the z-directional resolution of the model of theextension segment 802. In some embodiments, the z-directional resolutionof the model of the extension segment 802 may differ from thez-directional resolution of the nominal model 852. For example, thez-directional resolution of the model of the extension segment 802 maybe increased or decreased relative to the z-directional resolution ofthe nominal model 852.

As shown in FIG. 12A, an exemplary method 1200 of extending amodel-interface 804 may include, at step 1202, determining a height of aworkpiece 116 based at least in part on a digital representation of afield of view 114 that includes at least a portion of the workpiece, atstep 1204, determining a height for an extension segment 206 to beadditively printed on a workpiece-interface 120 of the workpiece 116,and at step 1206, extending the model-interface 804 in the z-directionby an amount corresponding to the height for the extension segment 206.The model-interface 804 may be extended in the z-direction within anominal model and then a resulting model of an extension segment 802 maybe extracted therefrom. Alternatively, the model-interface 804 may beextracted from the nominal model, and then the model-interface 804 maybe extended in the z-direction by an amount corresponding to the heightfor the extension segment 206 within a model of the extension segment802 being generated.

Exemplary methods of extending a model-interface 804 at step 1206 areshown in FIGS. 12B-12D. As shown in FIG. 12B, extending amodel-interface 804 in the z-direction may include, at step 1208,positioning the model-interface 804 at an elevation corresponding to abuild plane 122 of an additive manufacturing machine 104; at step 1210,positioning a copy of the model-interface a distance in the z-directionabove the model-interface 804 that corresponds to the height for theextension segment 206; and at step 1212, defining a model of anextension segment 802 extending in the z-direction from themodel-interface 804 to the copy of the model-interface 804.

As shown in FIG. 12C, extending a model-interface 804 in the z-directionmay include, at step 1214, positioning the model-interface 804 at anelevation corresponding to a build plane 122 of an additivemanufacturing machine 104; at step 1216, determining a nominalextended-plane 1104 of a nominal model corresponding to a top surface ofthe nominal model, and positioning the nominal extended-plane 1104 ofthe nominal model a distance in the z-direction above themodel-interface 804 that corresponds to the height for the extensionsegment 206; and at step 1218, defining a model of an extension segment802 extending in the z-direction from the model-interface 804 to thenominal extended-plane 1104.

As shown in FIG. 12D, extending a model-interface 804 in the z-directionmay include, at step 1220, positioning the model-interface 804 at anelevation corresponding to a build plane 122; at step 1222, determininga slice elevation for an extended-plane 1104 of a model of an extensionsegment 802; at step 1224, determining a nominal extended-plane 1104 ina nominal model, the nominal extended-plane 1104 being at an elevationcorresponding to the slice elevation for the model of the extensionsegment 802; and at step 1226, positioning the nominal extended-plane1104 a distance in the z-direction above the model-interface 804 thatcorresponds to the slice elevation.

In some embodiments, extending a model-interface 804 in the z-directionmay include, at step 1228, transforming a nominal extended-plane 1104,providing a transformed extended-plane 1104. The transforming of thenominal extended-plane 1104 may be based at least in part on acomparison of the nominal extended-plane 1104 to the model-interface804. Additionally, or in the alternative, the transforming of thenominal extended-plane 1104 may be based at least in part on theposition of the nominal extended-plane 1104 above the model-interface804 relative to the height for the extension segment 206. Thetransforming at step 1228 may include one more transforming operations,including those shown in FIGS. 10A-10D, or any other transformingoperation, such as aligning, altering, modifying, contorting,distorting, deforming, correcting, adjusting, revising, straightening,tilting, rotating, bending, twisting, or editing, as well ascombinations of these.

The particular transforming operation(s) at step 1228 may be selectedbased at least in part on the comparison of the nominal extended-plane1104 and/or the position of the nominal-extended plane 1104. In someembodiments, a transforming operation may include a smoothing factor,which may be configured to provide a graduated transition from amodel-interface 804 to a transformed extended-plane 1104. For example,an extended-plane 1104 may have a perimeter that differs from amodel-interface perimeter 806, and the smoothing factor may beconfigured to provide a gradual transition therebetween. The smoothingfactor may temper the transformation by a prorated amount depending onthe z-directional location of the extended-plane 1104.

An extended-plane 1104 at a z-direction position that corresponds to theheight of the extension segment 206 may not be transformed, such thatthe model of the extension segment 802 may gradually transition alongthe z-direction from a model-interface 804 conforming to aworkpiece-interface 120 to an extended-plane 1104 conforming to the topsurface 858 of the nominal model 852. Additionally, or in thealternative, an extended-plane 1104 at a z-direction position betweenthe model-interface 804 and the top surface of the extension segment 808may be transformed with a smoothing factor applied to thetransformation, so as to provide a transformed extended-plane 1104conforming to a perimeter partly between that of the model-interface 804and that of the top surface of the nominal model 852. Also, in someembodiments, an extended-plane 1104 at a z-direction position thatcorresponds to the height of the extension segment 206 may betransformed, for example, to provide top surface 808 of an extensionsegment 206 that differs from a top surface of the nominal model.

Still referring to FIG. 12D, the step of extending a model-interface 804in the z-direction may be performed for any number of slices. As shownin FIG. 12D, an exemplary method 1200 may include, at step 1230,determining whether the model of the extension segment 802 may includeanother slice. The number of slices may be predetermined, such as basedon the intended height of the model of the extension segment 802 and az-directional slice interval. A z-directional slice interval may dependon the desired z-directional resolution of the model of the extensionsegment 802. When there is another slice, the exemplary method 1200 mayinclude repeating steps 1222 through 1230. When step 1230 indicates thatthere are no additional slices, the exemplary method 1200 may proceedwith step 1232, which provides for defining a model of an extensionsegment 802 extending in the z-direction from the model-interface 804through each nominal or transformed extended-plane 1104, with the modelextending to the height for the extension segment 206. The model of theextension segment 802 may be defined at step 1232 concurrently as, orsubsequently after, each extension-plane is determined, positioned,and/or transformed at steps 1224, 1226, and 1228.

Referring again to FIG. 9A, a model of a plurality of extension segments802 may be output at step 914, such as to an extension segment-CAD model800 as shown in FIG. 8A. Each of the models of the extension segments802 may include a model-interface 804 aligned in the z-direction to aninterface plane in the extension segment-CAD model 800. The interfaceplane in the extension segment-CAD model 800 may correspond to a buildplane 122 of an additive printing machine 104. In this way, a pluralityof extension segments 206 may be additively printed onworkpiece-interfaces 120 of respective workpieces 116 as part of thesame build with each extension segment 206 properly aligning in thez-direction with the build plane 122. Referring again to FIG. 4, anexemplary method 400 of additively printing an extension segment 206includes, at step 408 generating a print command based at least in parton a digital representation of a field of view 114 captured by thevision system. FIG. 7B, shows an exemplary method 750 of generating aprint command for a plurality of slices of one or more extensionsegments 206. Now referring to FIG. 13, an exemplary print command 1300for a slice of a plurality of extension segments 206 is graphicallydepicted. As shown in FIG. 13, an exemplary print command 1300 foradditively printing a slice of an extension segment 206 may include aplurality of toolpaths 1302 respectively corresponding to the slice. Inan exemplary embodiment, the print command 1300 may be for a slice thatincludes a toolpath corresponding to the model-interface 804 of theplurality of extension segments 206. Additional print commands 1300 maybe generated for each respective slice as described with reference toFIG. 7B. The number of slices may depend on the size (e.g., height,thickness) of the extension segment(s) 206 in the extension segment-CADmodel 800, as well as the desired thickness of the layers of powder 126or other material that may be used to additively print the extensionsegment(s) 206.

In exemplary embodiments, the extension segment-CAD model 800 mayinclude a model of a plurality of extension segments 802, in which atleast a first model of a first extension segment 802 differs from atleast a second model of a second extension segment 802. The first modelof the first extension segment 802 may conform to and may besubstantially congruent with a first workpiece-interface 120 of a firstworkpiece 116, and the second model of the second extension segment 802may conform to and be substantially congruent with a secondworkpiece-interface 120 of a second workpiece 116. The print command1300 may include a first toolpath corresponding to a first slice of thefirst extension segment 206 and a second toolpath corresponding to asecond slice of the second extension segment 206, and the first toolpathmay differ from the second toolpath. For example, the first toolpath maydefine a first extension segment perimeter and the second toolpath maydefine a second extension segment perimeter, in which the firstextension segment perimeter differs from the second extension segmentperimeter, such as in respect of curvature, surface area, and/orgeometry.

Now referring to FIGS. 14-19, in some embodiments, an exemplary additivemanufacturing system 100 may be configured to perform a calibrationadjustment so as to prevent or mitigate discrepancies, biases,misalignments, calibration errors, or the like which may otherwise arisefrom time to time as between one or more aspects of the additivemanufacturing system 100. For example, a calibration adjustment may beconfigured to prevent or mitigate discrepancies, biases, misalignments,calibration errors, or the like between a vision system 102 and anadditive manufacturing machine 104, between a vision system 102 and oneor more CAD models generated based at least in part on one or moredigital images obtained using the vision system 102, or between one ormore CAD models and an additive manufacturing machine 104, as well ascombinations of these.

A calibration-CAD model may be utilized to calibrate an additivemanufacturing system 100, such as by performing a calibrationadjustment. FIG. 14 shows an exemplary calibration-CAD model 1400. Thecalibration-CAD model 1400 includes one or more model calibration marks1402. The one or more model calibration marks 1402 may respectively takethe form of or include a model of a registration point 202. For example,a model calibration mark 1402 may include a dot or other mark thatdefines a model of a registration point 202. The one or more modelcalibration marks 1402 may be respectively located at CAD-modelcoordinates corresponding respective ones of a plurality of registrationpoints 202 (FIGS. 2A and 2B). The registration points 202 maycorresponding to locations where respective ones of a plurality ofworkpieces 116 are to be situated when additively printing on therespective workpiece-interfaces 120 thereof.

One or more workpiece docks 210 may be respectively configured to securea plurality of workpieces 116 to a build plate 118, and the registrationpoints 202 may provide an indication of where the workpieces 116 areexpected to be located when secured to the build plate 118 and installedin the vision system 102 and/or the additive manufacturing machine 104.A calibration-CAD model 1400 may be utilized by an additivemanufacturing machine 104 to additively print model calibration marks1402 at locations corresponding to the registration points 202, such asat locations where the workpieces 116 are expected to be located whensecured to a build plate 118. For example, registration points 202represented by model calibration marks 1402 may correspond to locationsof one or more workpiece docks of a build plate 118.

In an exemplary embodiment, respective ones of the plurality of modelcalibration marks 1402 may have CAD model-coordinates that correspond torespective ones of the plurality of registration points 202. The modelcalibration marks 1402 may include a geometric shape or pattern, and atleast a portion of the geometric shape or pattern may have CADmodel-coordinates that correspond to a respective registration point202. In yet another exemplary embodiment, a model calibration mark 1402may include a contour corresponding to a perimeter of a model of anextension segment 802, such as a model-interface perimeter 806, and thecontour may have CAD model-coordinates corresponding to a location of aworkpiece 116 onto which an extension segment 206 may be additivelyprinted based on the model of the extension segment 802.

FIG. 15 shows an exemplary calibration surface 1500 that includes aplurality of printed calibration marks 1502 that were printed on thecalibration surface 1500 using the additive manufacturing machine 104.The printed calibration marks 1502 may have been printed on thecalibration surface 1500 based at least in part on a calibration-CADmodel 1400, such as the calibration-CAD model 1400 shown in FIG. 14. Thecalibration surface 1500 may include a build plate 118, and/or acalibration sheet applied to a build plate 118. An exemplary calibrationsheet may include transfer paper, carbon paper, or other materialsuitable for the additive manufacturing machine 104 to print thecalibration marks 1502 thereon. In an exemplary embodiment, the printedcalibration marks 1502 may be printed using an additive manufacturingtool such as a laser, but without utilizing powder 126 or other additivematerial. For example, an additive manufacturing machine 104 may includean energy source 142 such as a laser configured to additively print theplurality of extension segments 206 by marking the calibration surface1500 using the energy source 142.

FIG. 16 shows an exemplary digital representation 1600 of a field ofview 114 that includes a plurality of digitally represented calibrationmarks 1602 having been obtained using a vision system 102. The digitalrepresentation 1600 of the digitally represented calibration marks 1602in the field of view 114 may be identified using an edge detectionalgorithm. An exemplary edge detection algorithm may identify thedigitally represented calibration marks 1602 by identifying pixelswithin the digital representation 1600 of the field of view 114 thathave discontinuities, such as changes in brightness or contrast. Asshown in FIG. 16, the digital representation 1600 of the field of view114 may be compared to calibration-CAD model 1400. For example,respective ones of a plurality of digitally represented calibrationmarks 1602 may be compared to respective ones of a correspondingplurality of model calibration marks 1402.

FIG. 17 shows an exemplary comparison table 1700 illustrating anexemplary comparison of respective ones of a plurality of digitallyrepresented calibration marks 1602 to corresponding respective ones of aplurality of model calibration marks 1402. As shown in FIG. 17, such acomparison may include determining nominal coordinates 1702 for themodel calibration marks 1402 and determining measured coordinates 1704for the digitally represented calibrations marks 1602. Such a comparisonmay additionally include determining a system offset 1706, such as adifference between respective digitally represented calibrations mark1602 and corresponding model calibration marks 1402. Comparison data maybe obtained for each model calibration mark 1402, such as for eachcorresponding registration point 202.

A system offset 1706 may indicate a discrepancy, bias, misalignment,calibration error, or the like. A calibration adjustment may beperformed responsive to the comparison. The calibration adjustment maybe applied to any aspect of the additive manufacturing system 100,including the vision system 102, the additive manufacturing machine 104,or a control system 106. Additionally, or in the alternative, acalibration adjustment may be applied to one or more CAD models,including a library-CAD model and/or an extension segment-CAD model 800.For example, a calibration adjustment applied to a CAD model may beconfigured to align coordinates of the CAD model with coordinates of theadditive manufacturing system 100, such as vision system coordinatesand/or additive manufacturing machine coordinates. The calibrationadjustment may be applied so as to any one or more of the modelcalibration marks 1402 so as to align each model calibration mark 1402with a corresponding registration point 202. For example, a calibrationadjustment may be applied as to a model calibration mark 1402 when thesystem offset 1706 exceeds a threshold offset value.

Exemplary results of a calibration adjustment are schematicallyillustrated in FIGS. 18A-18C. FIG. 18A shows an exemplary digitalrepresentation 1800 of a workpiece-interface 120 obtained from a visionsystem 102 before calibration 1802 and after calibration 1804, such asfor a calibration adjustment applied to the vision system 102. FIG. 18Bshows an exemplary location of an extension segment 1810 additivelyprinted using an additive manufacturing machine 104 before calibration1812 and after calibration 1814, such as for a calibration adjustmentapplied to the additive manufacturing machine 104. FIG. 18C shows anexemplary location of a model of an extension segment 1820 in anextension-segment CAD model before calibration 1822 and aftercalibration 1824, such as for a calibration adjustment applied to theextension-segment CAD model.

Now referring to FIG. 19, exemplary methods of calibrating an additivemanufacturing system 100 will be described. An exemplary method 1900 mayinclude, at step 1902, comparing a digital representation of one or moredigitally represented calibration marks 1602 to a calibration-CAD model1400. The calibration-CAD model 1400 may include one or more modelcalibration marks 1402. The digital representation of the one or moredigitally represented calibration marks 1602 may have been obtainedusing a vision system 102, and the one or more printed calibration marks1502 may have been printed on a calibration surface 1500 according tothe calibration-CAD model 1400 using an additive manufacturing machine104. In some embodiments, the exemplary method 1900 may includeobtaining the digital representation of the one or more digitallyrepresented calibration marks 1602 using the vision system 102.

One or more calibration adjustments may be applied responsive to step1902. For example, in some embodiments, an exemplary method 1900 mayinclude, at step 1904, applying a calibration adjustment to one or moreCAD models based at least in part on the comparison. The calibrationadjustment may align the one or more CAD models with one or morecoordinates of the additive manufacturing system 100, such as visionsystem coordinates and/or additive manufacturing machine coordinates.For example, the calibration adjustment may align the coordinates of oneor more model calibration marks 1402 with coordinates of the additivemanufacturing machine 104. Additionally, or in the alternative, anexemplary method 1900 may include, at step 1906, applying a calibrationadjustment to the additive manufacturing system 100 based at least inpart on the comparison. The calibration adjustment applied to theadditive manufacturing system 100 may be configured to align one or morecoordinates of the vision system 102 with one or more coordinates of theadditive manufacturing machine 104.

In an exemplary embodiment, a method 1900 of calibrating an additivemanufacturing system 100 may include printing one or more modelcalibration marks 1402 on a calibration surface 1500 according to acalibration-CAD model 1400 using an additive manufacturing machine 104.The model calibration marks 1402 may be printed on the calibrationsurface 1500 at a plurality of registration points 202 according to thecalibration-CAD model 1400. The registration points 202 may haveCAD-model coordinates respectively corresponding to locations whererespective ones of a plurality of workpieces 116 are to be situated whenadditively printing respective ones of a plurality of extension segments206 onto the respective ones of the plurality of workpieces 116.

The digital representation of the digitally represented calibrationmarks 1602 may be compared to the model calibration marks 1402 in thecalibration CAD-model 1400 based at least in part on coordinates and/ordimensions of the model calibration marks 1402 and digitally representedcalibration marks 1602. For example, comparing the digitalrepresentation of the one or more digitally represented calibrationmarks 1602 to the model calibration marks 1402 in the calibration-CADmodel 1400 may include comparing one or more coordinates of the one ormore digitally represented calibration marks 1602 in the digitalrepresentation thereof with a corresponding one or more coordinates ofthe model calibration marks 1402 in the calibration-CAD model 1400, anddetermining one or more differences therebetween. The one or morecoordinates may include coordinates of respective ones of a plurality ofregistration points 202 respectively corresponding to locations ofrespective ones of a plurality of workpieces 116 onto which respectiveones of a plurality of extension segments 206 are to be additivelyprinted using the additive manufacturing machine 104. Additionally, orin the alternative, comparing the digital representation of the one ormore digitally represented calibration marks 1602 to the modelcalibration marks 1402 in the calibration-CAD model 1400 may includecomparing one or more dimensions of the one or more digitallyrepresented calibration marks 1602 in the digital representation thereofwith a corresponding one or more dimensions of the one or more modelcalibration marks 1402 in the calibration-CAD model 1400, anddetermining one or more differences therebetween.

Still referring to FIG. 19, the step 1904 of applying a calibrationadjustment to one or more CAD models may include transforming at least aportion of the one or more CAD models based at least in part on thecomparison at step 1902. The transforming may include rotating, bending,twisting, shifting, scaling, smoothing, aligning, offsetting, and/ormorphing at least a portion of the one or more CAD models.

In an exemplary embodiment, the one or more CAD models may include anextension segment-CAD model 800 that has a model of a plurality ofextension segments 802 respectively located at CAD model-coordinatescorresponding to respective ones of a plurality of registration points202 respectively corresponding to locations where respective ones of aplurality of workpieces 116 are to be situated when additively printingrespective ones of a plurality of extension segments 206 onto therespective ones of the plurality of workpieces 116. In some embodiments,applying a calibration adjustment to one or more CAD models at step 1904may include transforming at least a portion of the extension segment-CADmodel 800 based at least in part on the comparison so as to alignrespective ones of the plurality of models of extension segments 802 ofthe extension segment-CAD model 800 with the respective ones of theplurality of registration points 202 of the additive manufacturingsystem 100.

In still another exemplary embodiment, applying a calibration adjustmentto one or more CAD models at step 1904 may include generating anextension segment-CAD model 800. The generated extension segment-CADmodel 800 may include a model of a plurality of extension segments 802configured to be additively printed onto respective ones of a pluralityof workpieces 116, and the plurality of models of extension segments 802may be respectively located at CAD model-coordinates determined based atleast in part on the calibration adjustment. The plurality of models ofextension segments 802 may be aligned with respective ones of aplurality of registration points 202 of the additive manufacturingsystem 100. The plurality of registration points 202 may correspond tolocations where respective ones of a plurality of workpieces 116 are tobe situated when additively printing respective ones of a plurality ofextension segments 206 onto the respective ones of the plurality ofworkpieces 116.

Now referring to FIG. 20, further features of an additive manufacturingsystem 100 will be described. As shown in FIG. 20, an exemplary additivemanufacturing system 100 may include a control system 106. An exemplarycontrol system 106 includes a controller 2000 communicatively coupledwith a vision system 102 and/or an additive manufacturing machine 104.The controller 2000 may also be communicatively coupled with a userinterface 108 and/or a management system 110.

The controller 2000 may include one or more computing devices 2002,which may be located locally or remotely relative to the additive visionsystem 102 and/or the additive manufacturing machine 104. The one ormore computing devices 2002 may include one or more processors 2004 andone or more memory devices 2006. The one or more processors 2004 mayinclude any suitable processing device, such as a microprocessor,microcontroller, integrated circuit, logic device, and/or other suitableprocessing device. The one or more memory devices 2006 may include oneor more computer-readable media, including but not limited tonon-transitory computer-readable media, RAM, ROM, hard drives, flashdrives, and/or other memory devices.

The one or more memory devices 2006 may store information accessible bythe one or more processors 2004, including machine-executableinstructions 2008 that can be executed by the one or more processors2004. The instructions 2008 may include any set of instructions whichwhen executed by the one or more processors 2004 cause the one or moreprocessors 2004 to perform operations. In some embodiments, theinstructions 2008 may be configured to cause the one or more processors2004 to perform operations for which the controller 2000 and/or the oneor more computing devices 2002 are configured. Such operations mayinclude controlling the vision system 102 and/or the additivemanufacturing machine 104, including, for example, causing the visionsystem 102 to capture a digital representation of a field of view 114that includes a workpiece-interface 120 of one or more workpieces 116,generating one or more print commands 1300 based at least in part on theone or more digital representations of the one or more fields of view114, and causing the additive manufacturing machine 104 to additivelyprint respective ones of the plurality of extension segments 206 oncorresponding respective ones of the plurality of workpieces 116. Forexample, such instructions 2008 may include one or more print commands1300, which, when executed by an additive manufacturing machine 104,cause an additive-manufacturing tool to be oriented with respect to atoolpath that includes a plurality of toolpath coordinates and toadditively print at certain portions of the toolpath so as to additivelyprint a layer of the plurality of extension segments 206. The layer ofthe plurality of extension segments 206 may correspond to the slice ofthe extension segment-CAD model 800. Such operations may additionally oralternatively include calibrating an additive manufacturing system 100.

Such operations may further additionally or alternatively includereceiving inputs from the vision system 102, the additive manufacturingmachine 104, the user interface 108, and/or the management system 110.Such operations may additionally or alternatively include controllingthe vision system 102 and/or the additive manufacturing machine 104based at least in part on the inputs. Such operations may be carried outaccording to control commands provided by a control model 2010. Asexamples, exemplary control models 2010 may include one or more controlmodels 2010 configured to determine a workpiece-interface 120 of each ofa plurality of workpieces 116 from one or more digital representationsof one or more fields of view 114; one or more control models 2010configured to determine and/or generate an extension segment-CAD model800 based at least in part on the one or more digital representations ofthe one or more fields of view 114; and/or one or more control models2010 configured to slice an extension segment-CAD model 800 into aplurality of slices and/or to determine or generate a toolpath and anadditive printing area for each of the plurality of slices. Themachine-executable instructions 2008 can be software written in anysuitable programming language or can be implemented in hardware.Additionally, and/or alternatively, the instructions 2008 can beexecuted in logically and/or virtually separate threads on processors2004.

The memory devices 2006 may store data 2012 accessible by the one ormore processors 2004. The data 2012 can include current or real-timedata, past data, or a combination thereof. The data 2012 may be storedin a data library 2014. As examples, the data 2012 may include dataassociated with or generated by additive manufacturing system 100,including data 2012 associated with or generated by a controller 2000,the vision system 102, the additive manufacturing machine 104, the userinterface 108, the management system 110, and/or a computing device2002. The data 2012 may also include other data sets, parameters,outputs, information, associated with an additive manufacturing system100, such as those associated with the vision system 102, the additivemanufacturing machine 104, the user interface 108, and/or the managementsystem 110.

The one or more computing devices 2002 may also include a communicationinterface 2016, which may be used for communications with acommunications network 2018 via wired or wireless communication lines2020. The communication interface 2016 may include any suitablecomponents for interfacing with one or more network(s), including forexample, transmitters, receivers, ports, controllers, antennas, and/orother suitable components. The communication interface 2016 may allowthe computing device 2002 to communicate with the vision system 102, theadditive manufacturing machine 104. The communication network 2018 mayinclude, for example, a local area network (LAN), a wide area network(WAN), SATCOM network, VHF network, a HF network, a Wi-Fi network, aWiMAX network, a gatelink network, and/or any other suitablecommunications network for transmitting messages to and/or from thecontroller 2000 across the communication lines 2020. The communicationlines 2020 of communication network 2018 may include a data bus or acombination of wired and/or wireless communication links.

The communication interface 2016 may additionally or alternatively allowthe computing device 2002 to communicate with a user interface 108and/or a management system 110. The management system 110, which mayinclude a server 2022 and/or a data warehouse 2024. As an example, atleast a portion of the data 2012 may be stored in the data warehouse2024, and the server 2022 may be configured to transmit data 2012 fromthe data warehouse 2024 to the computing device 2002, and/or to receivedata 2012 from the computing device 2002 and to store the received data2012 in the data warehouse 2024 for further purposes. The server 2022and/or the data warehouse 2024 may be implemented as part of a controlsystem 106.

This written description uses exemplary embodiments to describe thepresently disclosed subject matter, including the best mode, and also toenable any person skilled in the art to practice such subject matter,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of the presently disclosedsubject matter is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A method of generating a CAD model that includesan extension segment conforming to a workpiece-interface, the methodcomprising: determining, in a library-CAD model, a nominalmodel-interface comprising a plane traversing the library-CAD model, thelibrary-CAD model comprising a nominal model of an extension segmentcorresponding to a workpiece or the library-CAD model comprising anominal model of the workpiece; comparing the nominal model-interface ofthe library-CAD model to a digital representation of aworkpiece-interface of the workpiece, the digital representation havingbeen obtained using a vision system that has a field of view includingthe workpiece-interface; and generating an extension segment-CAD modelcomprising a model of the extension segment, the extension segment-CADmodel differing from the library-CAD model in respect of at least one ofa transformation and an extension of the nominal model-interface basedat least in part on a comparison of the nominal model-interface to thedigital representation of the workpiece-interface, the model of theextension segment comprising a model-interface configured to beadditively printed on the workpiece-interface of the workpiece.
 2. Themethod of claim 1, wherein generating the extension segment-CAD modelcomprising the model of the extension segment comprises: extracting thenominal model-interface from a location in the nominal model thatcorresponds to an expected location of the workpiece-interface of theworkpiece.
 3. The method of claim 1, wherein generating the model of theextension segment comprises: transforming the nominal model-interfacebased at least in part on the comparison, providing a transformedmodel-interface conforming to the digital representation of theworkpiece-interface; and extending the transformed model-interface,providing the model of the extension segment, the model of the extensionsegment configured to be additively printed on the workpiece-interface.4. The method of claim 3, wherein transforming the nominalmodel-interface comprises performing at least one of the followingtransforming operations to at least a portion of the nominalmodel-interface: rotating, bending, twisting, shifting, scaling,smoothing, aligning, offsetting, and morphing.
 5. The method of claim 4,wherein transforming the nominal model-interface comprises: performing afirst transforming operation selected to align at least a first portionof the nominal model-interface with the digital representation of aworkpiece-interface, the first transforming operation comprising atleast one of a shifting transforming operation and a rotatingtransforming operation; and performing a second transforming operationselected to align at least a second portion of the nominalmodel-interface with the digital representation of theworkpiece-interface, the second transforming operation comprising atleast one of a bending transforming operation and a scaling transformingoperation.
 6. The method of claim 3, wherein extending the transformedmodel-interface comprises: determining a height of the workpiece basedat least in part on the digital representation of the field of view;determining a height for the extension segment to be additively printedon the workpiece-interface of the workpiece; and extending thetransformed model-interface in the z-direction by an amountcorresponding to the height for the extension segment.
 7. The method ofclaim 6, wherein extending the transformed model-interface in thez-direction by an amount corresponding to the height for the extensionsegment comprises: positioning the transformed model-interface at anelevation corresponding to a build plane of an additive manufacturingmachine; positioning a copy of the transformed model-interface adistance in the z-direction above the transformed model-interface thatcorresponds to the height for the extension segment; and defining themodel of the extension segment as extending in the z-direction from thetransformed model-interface to the copy of the transformedmodel-interface.
 8. The method of claim 1, wherein generating theextension segment-CAD model comprising the model of the extensionsegment comprises extending the nominal model-interface in thez-direction by an amount corresponding to the height for the extensionsegment, wherein extending the nominal model-interface comprises:positioning the nominal model-interface at an elevation corresponding toa build plane of an additive manufacturing machine; determining anominal extended-plane of the nominal model corresponding to a topsurface of the nominal model, and positioning the nominal extended-planeof the nominal model a distance in the z-direction above the nominalmodel-interface that corresponds to the height for the extensionsegment; and defining the model of the extension segment as extending inthe z-direction from the nominal model-interface to the nominalextended-plane.
 9. The method of claim 1, wherein generating theextension segment-CAD model comprising the model of the extensionsegment comprises extending the nominal model-interface in thez-direction by an amount corresponding to the height for the extensionsegment, wherein extending the nominal model-interface comprises:positioning the nominal model-interface at an elevation corresponding toa build plane of an additive manufacturing machine; determining a sliceelevation for an extended-plane of the model of the extension segment;determining a nominal extended-plane in the nominal model, the nominalextended-plane being at an elevation corresponding to the sliceelevation for the model of the extension segment; positioning thenominal extended-plane a distance in the z-direction above the nominalmodel-interface that corresponds to the slice elevation; transformingthe nominal extended-plane, providing a transformed extended-plane, thetransforming of the nominal extended-plane based at least in part on acomparison of at least one of: the nominal extended-plane to the nominalmodel-interface and the position of the nominal extended-plane above thenominal model-interface relative to the height for the extensionsegment; and defining the model of the extension segment as extending inthe z-direction from the nominal model-interface to the nominalextended-plane.
 10. The method of claim 1, wherein generating theextension segment-CAD model comprises: outputting the model of theextension segment to the extension segment-CAD model.
 11. The method ofclaim 1, comprising: generating image data comprising the digitalrepresentation of the workpiece-interface using the vision system. 12.The method of claim 1, wherein the workpiece comprises a compressorblade or a turbine blade for a turbomachine and wherein the extensionsegment comprises a blade tip.
 13. The method of claim 1, comprisinggenerating a CAD model that includes a plurality of extension segmentsconfigured to be respectively additively printed on a correspondingplurality of workpieces, the method comprising, for each respective oneof the plurality of workpieces: determining, in the library-CAD model, anominal model-interface comprising a plane traversing a respectivenominal model in the library-CAD model, the respective nominal modelcomprising a respective nominal model of the respective extensionsegment corresponding to a respective one of the plurality of workpiecesor the respective nominal model comprising a model of the respective oneof the plurality of workpieces; comparing the respective nominalmodel-interface of the library-CAD model to a digital representation ofa workpiece-interface of the respective one of the plurality ofworkpieces, the digital representation having been obtained using thevision system, the vision system having a field of view including theworkpiece-interface of the respective one of the plurality ofworkpieces; and generating the extension segment-CAD model comprisingthe model of the respective extension segment respectively correspondingto the respective one of the plurality of workpieces, the extensionsegment-CAD model differing form the library-CAD model in respect of atleast one of a transformation and an extension of the respective nominalmodel-interface based at least in part on a comparison of the nominalmodel-interface corresponding to the respective one of the plurality ofworkpieces to the digital representation of the respective one of theplurality of workpieces, the model of the extension segment configuredto be additively printed on the workpiece-interface of the respectiveone of the plurality of workpieces.
 14. The method of claim 13, whereingenerating the extension segment-CAD model comprising the model of theextension segment respectively corresponding to the respective one ofthe plurality of workpieces comprises: extracting the respective nominalmodel-interface from the respective nominal model at a location thatcorresponds to an expected location of the workpiece-interface of therespective one of the plurality of workpieces, the respective nominalmodel-interface corresponding to the respective one of the plurality ofworkpieces.
 15. The method of claim 13, wherein generating the extensionsegment-CAD model comprising the model of the extension segmentrespectively corresponding to the respective one of the plurality ofworkpieces comprises: transforming the respective nominalmodel-interface corresponding to the respective one of the plurality ofworkpieces based at least in part on the comparison, providing atransformed model-interface conforming to the digital representation ofthe workpiece-interface of the respective one of the plurality ofworkpieces; and extending the transformed model-interface, providing themodel of the respective extension segment configured to be additivelyprinted on the respective workpiece-interface of the respective one ofthe plurality of workpieces.
 16. The method of claim 13, whereingenerating the extension segment-CAD model comprises: outputting to theextension segment-CAD model, a model of a plurality of extensionsegments respectively configured to be additively printed on thecorresponding workpiece-interface of the respective ones of theplurality of workpieces.
 17. The method of claim 1, wherein generatingthe extension segment-CAD model comprising the model of the extensionsegment comprises: comparing the nominal model-interface of thelibrary-CAD model to a first digital representation of a firstworkpiece-interface of a first workpiece, the first digitalrepresentation having been obtained using the vision system, the visionsystem having a field of view including the first workpiece-interface;transforming the nominal model-interface based at least in part on thecomparison, providing a first transformed model-interface conforming tothe first digital representation; extending the first transformedmodel-interface, providing a first model of a first extension segmentconfigured to be additively printed on the first workpiece-interface ofthe first workpiece; comparing the nominal model-interface of thelibrary-CAD model to a second digital representation of a secondworkpiece-interface of a second workpiece, the second digitalrepresentation having been obtained using the vision system, the visionsystem having a field of view including the second workpiece-interface;transforming the nominal model-interface based at least in part on thecomparison, providing a second transformed model-interface conforming tothe second digital representation; extending the second transformedmodel-interface, providing a second model of a second extension segmentconfigured to be additively printed on the second workpiece-interface ofthe second workpiece; and outputting to the extension segment-CAD model,the first model of the first extension segment and the second model ofthe second extension segment.
 18. An additive manufacturing system,comprising: a controller operably coupled to a vision system and anadditive manufacturing machine, the controller comprising one or morecomputer readable medium and one or more processors, the one or morecomputer readable medium comprising computer-executable instructions,which, when executed by the one or more processors, causes the additivemanufacturing system to: determine, in a library-CAD model, a nominalmodel-interface comprising a plane traversing the library-CAD model, thelibrary-CAD model comprising a nominal model of an extension segmentcorresponding to a workpiece or the library-CAD model comprising anominal model of the workpiece; compare the nominal model-interface ofthe library-CAD model to a digital representation of aworkpiece-interface of the workpiece, the digital representation havingbeen obtained using a vision system that has a field of view includingthe workpiece-interface; and generate an extension segment-CAD modelcomprising a model of the extension segment, the extension segment-CADmodel differing from the library-CAD model in respect of at least one ofa transformation and an extension of the nominal model-interface basedat least in part on a comparison of the nominal model-interface to thedigital representation of the workpiece-interface, the model of theextension segment comprising a model-interface configured to beadditively printed on the workpiece-interface of the workpiece.
 19. Thesystem of claim 18, comprising at least one of: a vision systemconfigured to capture the digital representation of theworkpiece-interface; and an additive manufacturing machine configured toadditively print the extension segment on the workpiece.
 20. Anon-transitory computer readable medium comprising computer-executableinstructions, which, when executed by one or more processors of anadditive manufacturing system, causes the additive manufacturing systemto: determine, in a library-CAD model, a nominal model-interfacecomprising a plane traversing the library-CAD model, the library-CADmodel comprising a nominal model of an extension segment correspondingto a workpiece or the library-CAD model comprising a nominal model ofthe workpiece; compare the nominal model-interface of the library-CADmodel to a digital representation of a workpiece-interface of theworkpiece, the digital representation having been obtained using avision system that has a field of view including theworkpiece-interface; and generate an extension segment-CAD modelcomprising a model of the extension segment, the extension segment-CADmodel differing from the library-CAD model in respect of at least one ofa transformation and an extension of the nominal model-interface basedat least in part on a comparison of the nominal model-interface to thedigital representation of the workpiece-interface, the model of theextension segment comprising a model-interface configured to beadditively printed on the workpiece-interface of the workpiece.